EP7212 by bikash panda

EP7212

FEATURES

High-Performance, Low-Power System-on-Chip with LCD Controller and Digital Audio Interface (DAI)

n ARM720T processor — ARM7TDMI CPU — 8 K-bytes of four-way set-associative cache — MMU with 64-entry TLB (transition look-aside buffer) — Write Buffer — Windows CE enabled — Thumb code support enabled

OVERVIEW

n Dynamically programmable clock speeds of

18, 36, 49, and 74 MHz at 2.5 V n Performance matching 100-MHz Intel

Pentium-based PC n Ultra low power — Designed for applications that require long battery life while using standard AA/AAA batteries or rechargeable cells — Typical Power Numbers ● 90 mW at 74 MHz in the Operating State ● 30 mW at 18 MHz in the Operating State ● 10 mW in the Idle State (clock to the CPU stopped, everything else running) ● <1 mW in the Standby State (realtime clock ‘on’, everything else stopped) (cont.)

The EP7212 is designed for ultra-low-power applications such as organizers / PDAs, two-way pagers, smart cellular phones or any vertical PDA device that features the added capability of digital audio decompression. The core-logic functionality of the device is built around an ARM720T processor with 8 K-bytes of four-way set-associative unified cache and a write buffer. Incorporated into the ARM720T is an enhanced memory management unit (MMU) which allows for support of sophisticated operating systems like Microsoft Windows CE. (cont.)

Functional Block Diagram 13-MHZ INPUT 3.6864 MHZ

INTERNAL DATA BUS

PLL

D[0-31]

ARM720T 32.768 KHZ

32.768-KHZ OSCILLATOR

NPOR, RUN, RESET, WAKEUP

STATE CONTROL

BATOK, EXTPWR PWRFL, BATCHG

POWER MANAGEMENT

MEMORY CONTROLLER ARM7TDMI CPU CORE

CL-PS6700 INTF EXPANSION CNTRL

8-KBYTE CACHE

EINT[1-3], FIQ, MEDCHG FLASHING LED DRIVE PORTS A, B, D (8-BIT) PORT E (3-BIT) KEYBD DRIVERS (0-7) BUZZER DRIVE DC TO DC ADCCLK, ADCIN, ADCOUT, SMPCLK, ADCCS SSICLK, SSITXFR, SSITXDA, SSIRXDA, SSIRSFR

INTERRUPT CONTROLLER

MOE, MWE, RAS[0-1], CAS[0-3]

DRAM CNTRL

MMU WRITE BUFFER

RTC

PB[0-1], NCS[4-5] EXPCLK, WORD, NCS[0-3], EXPRDY, WRITE

INTERNAL ADDRESS BUS

A[0-27], DRA[0-12]

LCD DMA ICE-JTAG

TIMER COUNTERS(2)

GPIO PWM SSI1 (ADC)

ON-CHIP BOOT ROM

DAI SSI2 CODEC

Cirrus Logic, Inc. P.O. Box 17847, Austin, Texas 78760 (512) 445 7222 FAX: (512) 445 7851 http://www.cirrus.com

LCD CONTROLLER ON-CHIP SRAM 38,400 BYTES

EPB BRIDGE EPB BUS

TEST AND DEVELOPMENT LCD DRIVE

IrDA

LED AND PHOTODIODE

UART1

ASYNC INTERFACE 1

UART2

ASYNC INTERFACE 2

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EP7212 Low-Power System-on-Chip with LCD Controller and Digital Audio Interface

FEATURES (cont.) n Advanced audio decoder / decompression

capability — Allows for support of multiple audio decompression algorithms — Supports MPEG 1, 2, & 2.5 layer 3 audio decoding, including ISO compliant MPEG 1 & 2 layer 3 support for all standard sample rates and bit rates — Supports bit streams with adaptive bit rates — DAI (Digital Audio Interface) providing glueless interface to low-power DACs, ADCs, and Codecs n LCD controller — Interfaces directly to a single-scan panel monochrome LCD — Panel width size is programmable from 32 to 1024 pixels in 16-pixel increments — Video frame buffer size programmable up to 128 kbytes — Bits per pixel of 1, 2, or 4 bits n DRAM controller — Supports both 16- and 32-bit-wide DRAMs — EDO support (Fast Page Mode support for 13 MHz and 18 MHz operation only) n Memory controller — Decodes up to 6 separate memory segments of up to 256 Mbytes each — Each segment can be configured as 8, 16, or 32 bits wide and supports page-mode access — Programmable access time for conventional ROM / SRAM / FLASH memory — Supports Removable FLASH card interface — Enables connection to removable FLASH card for addition of expansion FLASH memory modules

n Synchronous serial interface — ADC (SSI) Interface: Master mode only; SPI and Microwire1-compatible (128 kbps operation) n On-chip ROM; for manufacturing support n 27-bits of general-purpose I/O — Three 8-bit and one 3-bit GPIO port — Supports scanning keyboard matrix n Two UARTs (16550 type) — Supports bit rates up to 115.2 kbps — Contains two 16-byte FIFOs for TX and RX — UART1 supports modem control signals n SIR (up to 115.2 kbps) infrared encoder / decoder — IrDA (Infrared Data Association) SIR protocol encoder / decoder n DC-to-DC converter interface (PWM) — Provides two 96-kHz clock outputs with programmable duty ratio (from 1-in-16 to 15-in-16) that can be used to drive a DC to DC converter n Two timer counters n 208-pin LQFP or new 256-ball PBGA packages n Evaluation kit available with BOM, schematics,

sample code, and design database n Support for up to two ultra-low-power CL-PS6700

PC Card controllers n Dedicated LED flasher pin from RTC n Full JTAG boundary scan and Embedded ICE support n Commercial operating temperature range

n 38,400 bytes (0x9600) of on-chip SRAM for fast

program execution and / or as a frame buffer

OVERVIEW (cont.) The EP7212 also includes a 32-bit Y2K-compliant realtime clock and comparator.

Power Management The EP7212 is designed for ultra-low-power operation. Its core operates at only 2.5 V, while its I/O has an operation range of 2.5 V–3.3 V. The device has three basic power states: Operating — This state is the full performance state. All the clocks and peripheral logic are enabled. Idle — This state is the same as the Operating State, except the CPU clock is halted while waiting for an event such as a key press.

Standby — This state is equivalent to the computer being switched off (no display), and the main oscillator shut down. An event such as a key press can wake-up the processor.

Memory Interfaces There are two main external memory interfaces. The first one is the ROM / SRAM / FLASH-style interface that has programmable wait-state timings and includes burst-mode capability, with eight chip selects decoding six 256-Mbyte sections of addressable space. For maximum flexibility, each bank can be specified to be 8, 16, or 32 bits wide. This allows the use of 8-bit-wide boot ROM options to minimize over-

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EP7212 Low-Power System-on-Chip with LCD Controller and Digital Audio Interface

OVERVIEW (cont.) all system cost. The on-chip boot ROM can be used in product manufacturing to serially download system code into system FLASH memory. To further minimize system memory requirements and cost, the ARM Thumb instruction set is supported, providing for the use of high-speed 32-bit operations in 16-bit op-codes and yielding industry-leading code density. The second is the programmable 16- or 32-bit-wide DRAM interface that allows direct connection of up to two banks of DRAM, each bank containing up to 256 Mbytes. To assure the lowest possible power consumption, the EP7212 supports self-refresh DRAMs, which are placed in a low-power state by the device when it enters the low-power Standby State. EDO and Fast Page DRAM are supported. A DMA address generator is also provided that fetches video display data for the LCD controller from main DRAM memory. The display frame buffer start address is programmable. In addition, the built-in LCD controller can utilize external or internal SRAM for memory, thus eliminating the need for DRAMs.

Digital Audio Capability The EP7212 uses its powerful 32-bit RISC processing engine to implement audio decompression algorithms in software. The nature of the on-board RISC processor and the availability of efficient C-compilers and other software development tools, ensures that a wide range of audio decompression algorithms can easily be ported to and run on the EP7212.

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Serial Interfaces The EP7212 includes two 16550-type UARTs for RS232 serial communications, both of which have two 16-byte FIFOs for receiving and transmitting data. The UARTs support bit rates up to 115.2 kbps. An IrDA SIR protocol encoder / decoder can be optionally switched into the RX / TX signals to / from one of the UARTs to enable these signals to drive an infrared communication interface directly.

Digital Audio Interface (DAI) The EP7212 integrates an interface to enable a direct connection to many low cost, low power, high quality audio converters. In particular, the DAI can directly interface with the Crystal CS43L41 / 42 / 43 lowpower audio DACs and the Crystal CS53L32 lowpower ADC. Some of these devices feature digital bass and treble boost, digital volume control and compressor-limiter functions.

Packaging The EP7212 is available in a 208-pin LQFP package and a 256-ball PBGA package.

System Design As shown in system block diagram, simply adding desired memory and peripherals to the highly integrated EP7212 completes a low-power system solution. All necessary interface logic is integrated on-chip.

EP7212 Low-Power System-on-Chip with LCD Controller and Digital Audio Interface

CRYSTAL

MOSCIN

CRYSTAL

RTCIN

DD[3:0] CL1 CL2 FM M

CS[4] PB0 EXPCLK

LCD MODULE

COL[7:0]

CL-PS6700 PC CARD CONTROLLER

PC CARD SOCKET

KEYBOARD

D[31:0]

PA[7:0]

A[27:0]

PB[7:0]

MOE WRITE

PD[7:0]

RAS[1] RAS[0]

× 16 DRAM

CAS[0] CAS[1]

× 16 DRAM

CAS[2] CAS[3]

EP7212

PE[2:0] POR PWRFL BATOK EXTPWR BATCHG RUN WAKEUP DRIVE[1:0] FB[1:0] NCS[0] NCS[1]

DC-TO-DC CONVERTERS

× 16 FLASH

SSICLK SSITXFR SSITXDA SSIRXDA

CODEC/SSI2/ DAI

× 16 FLASH

LEDDRV PHDIN

IR LED AND PHOTODIODE

EXTERNAL MEMORYMAPPED EXPANSION

BUFFERS

CS[2] CS[3]

BUFFERS AND LATCHES

RxD1/2 TxD1/2 DSR CTS DCD ADCCLK ADCCS ADCOUT ADCIN SMPCLK

DC INPUT

BATTERY

× 16 FLASH

CS[n] WORD

ADDITIONAL I/O

POWER SUPPLY UNIT AND COMPARATORS

2× RS-232 TRANSCEIVERS

ADC

DIGITIZER

A EP7212–Based System

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EP7212

EP7212 TABLE OF CONTENTS 1. CONVENTIONS ...................................................................................................................... 11 1.1 Acronyms and Abbreviations ............................................................................................ 11 1.2 Units of Measurement ...................................................................................................... 12 1.3 General Conventions ........................................................................................................ 12 1.4 Pin Description Conventions ............................................................................................. 12 2. PIN INFORMATION ................................................................................................................ 13 2.1 208-Pin LQFP Pin Diagram .............................................................................................. 13 2.2 Pin Descriptions ................................................................................................................ 14 2.2.1 External Signal Functions ................................................................................... 14 2.2.2 SSI/Codec/DAI Pin Multiplexing ............................................................................. 18 2.2.3 Output Bi-Directional Pins .................................................................................... 18 3. FUNCTIONAL DESCRIPTION ............................................................................................... 19 3.1 CPU Core .......................................................................................................................... 20 3.2 State Control ..................................................................................................................... 21 3.2.1 Standby State .......................................................................................................... 21 3.2.1.1 UART in Standby State ............................................................................... 22 3.2.2 Idle State ................................................................................................................. 23 3.2.3 Keyboard Interrupt ................................................................................................... 23 3.3 Power-Up Sequence ......................................................................................................... 23 3.4 Resets ............................................................................................................................... 24 3.5 Clocks ............................................................................................................................... 25 3.5.1 On-Chip PLL ............................................................................................................ 25 3.5.1.1 Characteristics of the PLL Interface ............................................................ 25 3.5.2 External Clock Input (13 MHz) ................................................................................ 26 3.5.3 Dynamic Clock Switching When in the PLL Clocking Mode .................................... 26 3.6 Interrupt Controller ............................................................................................................ 27 3.6.1 Interrupt Latencies in Different States ..................................................................... 27 3.6.1.1 Operating State ........................................................................................... 27 3.6.1.2 Idle State ..................................................................................................... 29 3.6.1.3 Standby State .............................................................................................. 29 3.7 EP7212 Boot ROM .......................................................................................................... 29 3.8 Memory and I/O Expansion Interface ............................................................................... 30 3.9 DRAM Controller with EDO Support ................................................................................. 31 3.10 CL-PS6700 PC Card Controller Interface ....................................................................... 33 3.11 Endianness ..................................................................................................................... 36 3.12 Internal UARTs (Two) and SIR Encoder ......................................................................... 36 3.13 Serial Interfaces .............................................................................................................. 38

Contacting Cirrus Logic Support For a complete listing of Direct Sales, Distributor, and Sales Representative contacts, visit the Cirrus Logic web site at: http://www.cirrus.com/corporate/contacts/ Preliminary product information describes products which are in production, but for which full characterization data is not yet available. Advance product information describes products which are in development and subject to development changes. Cirrus Logic, Inc. has made best efforts to ensure that the information contained in this document is accurate and reliable. However, the information is subject to change without notice and is provided â&#x20AC;&#x153;AS ISâ&#x20AC;? without warranty of any kind (express or implied). No responsibility is assumed by Cirrus Logic, Inc. for the use of this information, nor for infringements of patents or other rights of third parties. This doc ument is the property of Cirrus Logic, Inc. and implies no license under patents, copyrights, trademarks, or trade secrets. No part of this publication may be copied reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photographic, or otherwise) without the prior written con sent of Cirrus Logic, Inc. Items from any Cirrus Logic website or disk may be printed for use by the user. However, no part of the printout or electronic files may be copied, reproduced, stored in a retrieval system, or transmitted, in any form or by any means (electronic, mechanical, photographic, or otherwise) without the prio written consent of Cirrus Logic, Inc.Furthermore, no part of this publication may be used as a basis for manufacture or sale of any items without the prior written consen of Cirrus Logic, Inc. The names of products of Cirrus Logic, Inc. or other vendors and suppliers appearing in this document may be trademarks or service marks o their respective owners which may be registered in some jurisdictions. A list of Cirrus Logic, Inc. trademarks and service marks can be found at http://www.cirrus.com

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EP7212 3.13.1 Codec Sound Interface .......................................................................................... 39 3.13.2 Digital Audio Interface ............................................................................................ 40 3.13.2.1 DAI Operation ............................................................................................ 41 3.13.2.2 DAI Frame Format ..................................................................................... 41 3.13.2.3 DAI Signals ................................................................................................ 42 3.13.3 ADC Interface — Master Mode Only SSI1 (Synchronous Serial Interface) ........... 42 3.13.4 Master / Slave SSI2 (Synchronous Serial Interface 2) .......................................... 43 3.13.4.1 Read Back of Residual Data ..................................................................... 44 3.13.4.2 Support for Asymmetric Traffic .................................................................. 45 3.13.4.3 Continuous Data Transfer ......................................................................... 45 3.13.4.4 Discontinuous Clock .................................................................................. 45 3.13.4.5 Error Conditions ......................................................................................... 46 3.13.4.6 Clock Polarity ............................................................................................. 46 3.14 LCD Controller with Support for On-Chip Frame Buffer .................................................. 46 3.15 Timer Counters ............................................................................................................... 47 3.15.1 Free Running Mode ............................................................................................... 48 3.15.2 Prescale Mode ....................................................................................................... 48 3.16 Real Time Clock .............................................................................................................. 49 3.16.1 Characteristics of the Real Time Clock Interface ................................................... 49 3.17 Dedicated LED Flasher ................................................................................................... 49 3.18 Two PWM Interfaces ....................................................................................................... 49 3.19 Boundary Scan ................................................................................................................ 50 3.20 In-Circuit Emulation ......................................................................................................... 50 3.20.1 Introduction ............................................................................................................ 50 3.20.2 Functionality ........................................................................................................... 51 3.21 Maximum EP7212-Based System .................................................................................. 51 4. MEMORY MAP ....................................................................................................................... 53 5. REGISTER DESCRIPTIONS .................................................................................................. 54 5.1 Internal Registers .............................................................................................................. 54 5.1.1 PADR Port A Data Register ..................................................................................... 57 5.1.2 PBDR Port B Data Register ..................................................................................... 57 5.1.3 PDDR Port D Data Register .................................................................................... 57 5.1.4 PADDR Port A Data Direction Register ................................................................... 58 5.1.5 PBDDR Port B Data Direction Register ................................................................... 58 5.1.6 PDDDR Port D Data Direction Register ................................................................... 58 5.1.7 PEDR Port E Data Register ..................................................................................... 58 5.1.8 PEDDR Port E Data Direction Register ................................................................... 58 5.2 SYSTEM Control Registers ............................................................................................... 58 5.2.1 SYSCON1 The System Control Register 1 ............................................................. 58 5.2.2 SYSCON2 System Control Register 2 ..................................................................... 61 5.2.3 SYSCON3 System Control Register 3 ..................................................................... 63 5.2.4 SYSFLG1 — The System Status Flags Register .................................................... 64 5.2.5 SYSFLG2 System Status Register 2 ....................................................................... 66 5.3 Interrupt Registers ............................................................................................................. 67 5.3.1 INTSR1 Interrupt Status Register 1 ......................................................................... 67 5.3.2 INTMR1 Interrupt Mask Register 1 .......................................................................... 68 5.3.3 INTSR2 Interrupt Status Register 2 ......................................................................... 69 5.3.4 INTMR2 Interrupt Mask Register 2 .......................................................................... 69 5.3.5 INTSR3 Interrupt Status Register 3 ......................................................................... 70 5.3.6 INTMR3 Interrupt Mask Register 3 .......................................................................... 70 5.4 Memory Configuration Registers ....................................................................................... 71 5.4.1 MEMCFG1 Memory Configuration Register 1 ......................................................... 71 5.4.2 MEMCFG2 Memory Configuration Register 2 ......................................................... 71

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EP7212 5.5 Timer / Counter Registers ................................................................................................. 74 5.5.1 TC1D Timer Counter 1 Data Register ..................................................................... 74 5.5.2 TC2D Timer Counter 2 Data Register ..................................................................... 74 5.5.3 RTCDR Real Time Clock Data Register ................................................................. 74 5.5.4 RTCMR Real Time Clock Match Register ............................................................... 74 5.6 LEDFLSH Register ........................................................................................................... 75 5.7 PMPCON Pump Control Register ..................................................................................... 76 5.8 CODR — The CODEC Interface Data Register ................................................................ 77 5.9 UART Registers ................................................................................................................ 77 5.9.1 UARTDR1–2, UART1–2 Data Registers ................................................................. 77 5.9.2 UBRLCR1–2 UART1–2 Bit Rate and Line Control Registers ................................. 78 5.10 LCD Registers ................................................................................................................. 79 5.10.1 LCDCON — The LCD Control Register ................................................................ 79 5.10.2 PALLSW Least Significant Word — LCD Palette Register ................................... 80 5.10.3 PALMSW Most Significant Word — LCD Palette Register ................................... 81 5.10.4 FBADDR LCD Frame Buffer Start Address ........................................................... 81 5.11 SSI Register .................................................................................................................... 82 5.11.1 SYNCIO Synchronous Serial ADC Interface Data Register .................................. 82 5.12 STFCLR Clear all ‘Start Up Reason’ flags location ......................................................... 83 5.13 End Of Interrupt Locations .............................................................................................. 83 5.13.1 BLEOI Battery Low End of Interrupt ...................................................................... 83 5.13.2 MCEOI Media Changed End of Interrupt .............................................................. 83 5.13.3 TEOI Tick End of Interrupt Location ...................................................................... 83 5.13.4 TC1EOI TC1 End of Interrupt Location ................................................................. 83 5.13.5 TC2EOI TC2 End of Interrupt Location ................................................................. 84 5.13.6 RTCEOI RTC Match End of Interrupt .................................................................... 84 5.13.7 UMSEOI UART1 Modem Status Changed End of Interrupt .................................. 84 5.13.8 COEOI Codec End of Interrupt Location ............................................................... 84 5.13.9 KBDEOI Keyboard End of Interrupt Location ........................................................ 84 5.13.10 SRXEOF End of Interrupt Location ..................................................................... 84 5.14 State Control Registers ................................................................................................... 84 5.14.1 STDBY Enter the Standby State Location ............................................................. 84 5.14.2 HALT Enter the Idle State Location ....................................................................... 84 5.15 SS2 Registers ................................................................................................................. 85 5.15.1 SS2DR Synchronous Serial Interface 2 Data Register ......................................... 85 5.15.2 SS2POP Synchronous Serial Interface 2 Pop Residual Byte ............................... 85 5.16 DAI Register Definitions .................................................................................................. 85 5.16.1 DAIR DAI Control Register .................................................................................... 86 5.16.1.1 DAI Enable (DAIEN) .................................................................................. 87 5.16.1.2 DAI Interrupt Generation ........................................................................... 87 5.16.1.3 Left Channel Transmit FIFO Interrupt Mask (LCTM) ................................. 87 5.16.1.4 Left Channel Receive FIFO Interrupt Mask (LARM) ................................. 87 5.16.1.5 Right Channel Transmit FIFO Interrupt Mask (RCTM) .............................. 87 5.16.1.6 Right Channel Receive FIFO Interrupt Mask (RCRM) .............................. 88 5.16.1.7 Loopback Mode (LBM) .............................................................................. 88 5.16.2 DAI Data Registers ................................................................................................ 89 5.16.2.1 DAIDR0 DAI Data Register 0 .................................................................... 89 5.16.2.2 DAIDR1 DAI Data Register 1 .................................................................... 90 5.16.2.3 DAIDR2 DAI Data Register 2 .................................................................... 91 5.16.3 DAISR DAI Status Register ................................................................................... 92 5.16.3.1 Right Channel Transmit FIFO Service Request Flag (RCTS) ................... 94 5.16.3.2 Right Channel Receive FIFO Service Request Flag (RCRS) ................... 94 5.16.3.3 Left Channel Transmit FIFO Service Request Flag (LCTS) ...................... 94

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EP7212 5.16.3.4 Left Channel Receive FIFO Service Request Flag (LCRS) ....................... 94 5.16.3.5 Right Channel Transmit FIFO Underrun Status (RCTU) ........................... 94 5.16.3.6 Right Channel Receive FIFO Overrun Status (RCRO) ............................. 94 5.16.3.7 Left Channel Transmit FIFO Underrun Status (LCTU) .............................. 95 5.16.3.8 Left Channel Receive FIFO Overrun Status (LCRO) ................................ 95 5.16.3.9 Right Channel Transmit FIFO Not Full Flag (RCNF) ................................. 95 5.16.3.10 Right Channel Receive FIFO Not Empty Flag (RCNE) ........................... 95 5.16.3.11 Left Channel Transmit FIFO Not Full Flag (LCNF) .................................. 95 5.16.3.12 Left Channel Receive FIFO Not Empty Flag (LCNE) .............................. 95 5.16.3.13 FIFO Operation Completed Flag (FIFO) .................................................. 95 6. ELECTRICAL SPECIFICATIONS .......................................................................................... 96 6.1 Absolute Maximum Ratings .............................................................................................. 96 6.2 Recommended Operating Conditions .............................................................................. 96 6.3 DC Characteristics ............................................................................................................ 96 6.4 AC Characteristics ............................................................................................................ 98 6.5 I/O Buffer Characteristics ................................................................................................ 110 6.6 JTAG Boundary Scan Signal Ordering ........................................................................... 111 7. TEST MODES ....................................................................................................................... 114 7.1 Oscillator and PLL Bypass Mode .................................................................................... 114 7.2 Oscillator and PLL Test Mode ......................................................................................... 114 7.3 Debug / ICE Test Mode .................................................................................................. 115 7.4 Hi-Z (System) Test Mode ............................................................................................... 115 7.5 Software Selectable Test Functionality .......................................................................... 115 8. PIN INFORMATION .............................................................................................................. 116 8.1 208-Pin LQFP Pin Diagram ............................................................................................. 116 8.2 208-Pin LQFP Numeric Pin Listing ................................................................................. 117 8.3 256-Pin PBGA Pin Diagram ............................................................................................ 120 8.4 256-Ball PBGA Ball Listing .............................................................................................. 121 9. PACKAGE SPECIFICATIONS ............................................................................................. 125 9.1 208-Pin LQFP Package Outline Drawing ....................................................................... 125 9.2 EP7212 256-Ball PBGA (17 × 17 × 1.53-mm Body) Dimensions ................................... 126 10. ORDERING INFORMATION ............................................................................................... 127 11. APPENDIX A: BOOT CODE .............................................................................................. 128 12. INDEX ................................................................................................................................. 133

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EP7212 LIST OF FIGURES Figure 1. 208-Pin LQFP (Low Profile Quad Flat Pack) Pin Diagram ............................................ 13 Figure 2. EP7212 Block Diagram.................................................................................................. 20 Figure 3. State Diagram ................................................................................................................ 21 Figure 4. CLKEN Timing Entering the Standby State ................................................................... 26 Figure 5. CLKEN Timing Entering the Standby State ................................................................... 26 Figure 6. Codec Interrupt Timing .................................................................................................. 40 Figure 7. DAI Interface .................................................................................................................. 41 Figure 8. EP7212 Rev C - Digital Audio Interface Timing â&#x20AC;&#x201C; MSB / Left Justified format............... 42 Figure 9. SSI2 Port Directions in Slave and Master Mode............................................................ 44 Figure 10. Residual Byte Reading ................................................................................................ 45 Figure 11. Video Buffer Mapping .................................................................................................. 48 Figure 12. A Maximum EP7212 Based System ............................................................................ 52 Figure 13. Consecutive Memory Read Cycles with Minimum Wait States ................................. 100 Figure 14. Sequential Page Mode Read Cycles with Minimum Wait States............................... 101 Figure 15. Consecutive Memory Write Cycles with Minimum Wait States.................................. 102 Figure 16. DRAM Read Cycles at 13 MHz and 18.432 MHz ...................................................... 103 Figure 17. DRAM Read Cycles at 36 MHz.................................................................................. 104 Figure 18. DRAM Write Cycles at 13 MHz and 18 MHz ............................................................. 105 Figure 19. DRAM Write Cycles at 36 MHz.................................................................................. 106 Figure 20. Video Quad Word Read from DRAM at 13 MHz and 18 MHz ................................... 107 Figure 21. Quad Word Read from DRAM at 36 MHz.................................................................. 107 Figure 22. DRAM CAS Before RAS Refresh Cycle at 13 MHz and 18 MHz............................... 108 Figure 23. DRAM CAS Before RAS Refresh Cycle at 36 MHz ................................................... 109 Figure 24. LCD Controller Timings.............................................................................................. 109 Figure 25. SSI Interface for AD7811/2 ........................................................................................ 110 Figure 26. SSI2 Interface Timings............................................................................................... 110 Figure 27. 208-Pin LQFP (Low Profile Quad Flat Pack) Pin Diagram ........................................ 116 Figure 28. 256-Ball Plastic Ball Grid Array Diagram ................................................................... 120

LIST OF TABLES Table 1. Acronyms and Abbreviations .......................................................................................... 11 Table 2. Unit of Measurement....................................................................................................... 12 Table 3. Pin Description Conventions ........................................................................................... 12 Table 4. External Signal Functions ............................................................................................... 14 Table 5. SSI/Codec/DAI Pin Multiplexing...................................................................................... 18 Table 6. Output Bi-Directional Pins ............................................................................................... 18 Table 7. Peripheral Status in Different Power Management States.............................................. 22 Table 8. Exception Priority Handling ............................................................................................. 27 Table 9. Interrupt Allocation in the First Interrupt Register............................................................ 28 Table 10. Interrupt Allocation in the Second Interrupt Register .................................................... 28 Table 11. Interrupt Allocation in the Third Interrupt Register ........................................................ 28 Table 12. External Interrupt Source Latencies.............................................................................. 30 Table 13. Chip Select Address Ranges After Boot From On-Chip Boot ROM.............................. 30 Table 14. Boot Options ................................................................................................................. 31 Table 15. Physical to DRAM Address Mapping ............................................................................ 32 Table 16. DRAM Address Mapping When Connected to an External 32-Bit DRAM Memory System ............................................................................................................... 33 Table 17. CL-PS6700 Memory Map.............................................................................................. 34 Table 18. Space Field Decoding ................................................................................................... 34

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EP7212 Table 19. Effect of Endianness on Read Operations .................................................................... 37 Table 20. Effect of Endianness on Write Operations .................................................................... 37 Table 21. Serial Interface Options................................................................................................. 39 Table 22. Serial-Pin Assignments ................................................................................................. 39 Table 23. ADC Interface Operation Frequencies .......................................................................... 43 Table 24. Instructions Supported in JTAG Mode .......................................................................... 50 Table 25. Device ID Register ........................................................................................................ 51 Table 26. EP7212 Memory Map in External Boot Mode ............................................................... 53 Table 27. EP7212 Internal Registers (Little Endian Mode) ........................................................... 55 Table 28. EP7212 Internal Registers (Big Endian Mode).............................................................. 57 Table 29. SYSCON1 ..................................................................................................................... 59 Table 30. SYSCON2 ..................................................................................................................... 61 Table 31. SYSCON3 ..................................................................................................................... 63 Table 32. SYSFLG ........................................................................................................................ 64 Table 33. SYSFLG2 ...................................................................................................................... 66 Table 34. INTSR1.......................................................................................................................... 67 Table 35. INSTR2.......................................................................................................................... 69 Table 36. INTSR3.......................................................................................................................... 70 Table 37. Values of the Bus Width Field ....................................................................................... 72 Table 38. Values of the Wait State Field at 13 MHz and 18 MHz ................................................. 72 Table 39. Values of the Wait State Field at 36 MHz...................................................................... 72 Table 40. MEMCFG ...................................................................................................................... 73 Table 41. LED Flash Rates ........................................................................................................... 75 Table 42. LED Duty Ratio.............................................................................................................. 75 Table 43. PMPCON....................................................................................................................... 76 Table 44. Sense of PWM control lines .......................................................................................... 76 Table 45. UARTDR1-2 UART1-2 .................................................................................................. 77 Table 46. UBRLCR1-2 UART1-2 .................................................................................................. 78 Table 47. LCDCON ....................................................................................................................... 79 Table 48. Grayscale Value to Color Mapping................................................................................ 81 Table 49. SYNCIO......................................................................................................................... 82 Table 50. DAI Control Register ..................................................................................................... 86 Table 51. DAI Data Register 0 ...................................................................................................... 89 Table 52. DAI Data Register 1 ...................................................................................................... 90 Table 53. DAI Data Register 2 ...................................................................................................... 91 Table 54. DAI Control, Data and Status Register Locations ......................................................... 92 Table 55. absolute Maximum Ratings ........................................................................................... 96 Table 56. Recommended Operating Conditions ........................................................................... 96 Table 57. DC Characteristics ........................................................................................................ 96 Table 58. AC Timing Characteristics............................................................................................. 98 Table 59. Timing Characteristics................................................................................................... 99 Table 60. I/O Buffer Output Characteristics ................................................................................ 111 Table 61. 208-Pin LQFP Numeric Pin Listing.............................................................................. 111 Table 62. EP7212 Hardware Test Modes ................................................................................... 114 Table 63. Oscillator and PLL Test Mode Signals ........................................................................ 115 Table 64. Software Selectable Test Functionality ....................................................................... 115 Table 65. 208-Pin LQFP Numeric Pin Listing.............................................................................. 117 Table 66. 256-Ball PBGA Ball Listing.......................................................................................... 121

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EP7212 1. CONVENTIONS This section presents acronyms, abbreviations, units of measurement, and conventions used in this data sheet.

1.1

Acronyms and Abbreviations

Table 1 lists abbreviations and acronyms used in this data sheet. Acronym/ Abbreviation

Definition

Acronym/ Abbreviation

Definition

PIA

peripheral interface adapter.

PLL

phase locked loop.

PSU

power supply unit.

p/u

pull-up resistor.

RAM

random access memory.

RISC

reduced instruction set computer.

ROM

read-only memory.

RTC

Real Time Clock.

SIR

slow (9600â&#x20AC;&#x201C;115.2 kbps) infrared.

SRAM

static random access memory.

SSI

synchronous serial interface.

TAP

test access port.

alternating current.

A/D

analog-to-digital.

ADC

analog-to-digital converter.

CMOS

complementary metal oxide semiconductor.

CODEC

coder / decoder.

TLB

translation lookaside buffer.

CPU

central processing unit.

UART

D/A

digital-to-analog.

universal asynchronous receiver.

direct current.

DMA

direct-memory access.

EPB

embedded peripheral bus.

FCS

frame check sequence.

FIFO

first in / first out.

GPIO

general purpose I/O.

ICT

in circuit test.

infrared.

IrDA

Infrared Data Association.

JTAG

Joint Test Action Group.

LCD

liquid crystal display.

LED

light-emitting diode.

LQFP

low profile quad flat pack.

LSB

least significant bit.

MIPS

millions of instructions per second.

MMU

memory management unit.

MSB

most significant bit.

PBGA

plastic ball grid array.

PCB

printed circuit board.

PDA

personal digital assistant.

Table 1. Acronyms and Abbreviations (cont.)

Table 1. Acronyms and Abbreviations

DS474PP1

EP7212 1.2

Units of Measurement

Symbol

Unit of Measure

a 0x at the beginning. For example, 0x14 and 03CAh are hexadecimal numbers. Binary numbers are enclosed in single quotation marks when in text (for example, ‘11’ designates a binary number). Numbers not indicated by an ‘h’, 0x or quotation marks are decimal.

°C

degree Celsius

hertz (cycle per second)

kbits/s

kilobits per second

kbyte

kilobyte (1,024 bytes)

kHz

kilohertz

kΩ

kilohm

Mbps

megabits (1,048,576 bits) per second

Mbyte

megabyte (1,048,576 bytes)

MHz

megahertz (1,000 kilohertz)

µA

microampere

µF

microfarad

µW

microwatt

µs

microsecond (1,000 nanoseconds)

milliampere

milliwatt

millisecond (1,000 microseconds)

nanosecond

Input

volt

Output

watt

I/O

Input or Output

Table 2. Unit of Measurement

1.3

Registers are referred to by acronym, as listed in the tables on the previous page, with bits listed in brackets MSB-to-LSB separated by a colon (:) (for example, CODR[7:0]), or LSB-to-MSB separated by a hyphen (for example, CODR[0–2]). The use of ‘tbd’ indicates values that are ‘to be determined’, ‘n/a’ designates ‘not available’, and ‘n/c’ indicates a pin that is a ‘no connect’.

1.4

Pin Description Conventions

Abbreviations used for signal directions are listed in Table 3. Abbreviation

Direction

Table 3. Pin Description Conventions

General Conventions

Hexadecimal numbers are presented with all letters in uppercase and a lowercase ‘h’ appended or with

DS474PP1

EP7212 2. PIN INFORMATION 208-Pin LQFP Pin Diagram

156 155 154 153 152 151 150 149 148 147 146 145 144 143 142 141 140 139 138 137 136 135 134 133 132 131 130 129 128 127 126 125 124 123 122 121 120 119 118 117 116 115 114 113 112 111 110 109 108 107 106 105

NURESET NMEDCHG/NBROM NPOR BATOK NEXTPWR NBATCHG D[7] VSSIO A[7] D[8] A[8] D[9] A[9] D[10] A[10] D[11] VSSIO VDDIO A[11] D[12] A[12] D[13] A[13] D[14] A[14] D[15] A[15]/DRA[12] D[16] A[16]/DRA[11] D[17] A[17]/DRA[10] NTRST VSSIO VDDIO D[18] A[18/DRA[9] D[19] A[19]/DRA[8] D[20] A[20]/DRA[7] VSSIO D[21] A[21]/DRA[6] D[22] A[22]/DRA[5] D[23] A[23]/DRA[4] D[24] VSSIO VDDIO A[24]/DRA[3] HALFWORD

2.1

EP7212 208-Pin LQFP (Top View)

104 103 102 101 100 99 98 97 96 95 94 93 92 91 90 89 88 87 86 85 84 83 82 81 80 79 78 77 76 75 74 73 72 71 70 69 68 67 66 65 64 63 62 61 60 59 58 57 56 55 54 53

D[25] A[25]/DRA[2] D[26] A[26]/DRA[1] D[27] A[27]/DRA[0] VSSIO D[28] D[29] D[30] D[31] BUZ COL[0] COL[1] TCLK VDDIO COL[2] COL[3] COL[4] COL[5] COL[6] COL[7] FB[0] VSSIO FB[1] SMPCLK ADCOUT ADCCLK DRIVE[0] DRIVE[1] VDDIO VSSIO VDDCORE VSSCORE NADCCS ADCIN SSIRXFR SSIRXDA SSITXDA SSITXFR VSSIO SSICLK PD[0]/LEDFLSH PD[1] PD[2] PD[3] TMS VDDIO PD[4] PD[5] PD[6] PD[7]

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52

157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208

NCS[5] VDDIO VSSIO EXPCLK WORD WRITE RUN/CLKEN EXPRDY TXD[2] RXD[2] TDI VSSIO PB[7] PB[6] PB[5] PB[4] PB[3] PB[2] PB[1]/PRDY[2] PB[0]/PRDY[1] VDDIO TDO PA[7] PA[6] PA[5] PA[4] PA[3] PA[2] PA[1] PA[0] LEDDRV TXD[1] VSSIO PHDIN CTS RXD[1] DCD DSR NTEST[1] NTEST[0] EINT[3] NEINT[2] NEINT[1] NEXTFIQ PE[2]/CLKSEL PE[1]BOOTSEL[1] PE[0]BOOTSEL[0] VSSRTC RTCOUT RTCIN VDDRTC N/C

VDDOSC MOSCIN MOSCOUT VSSOSC WAKEUP NPWRFL A[6] D[6] A[5] D[5] VDDIO VSSIO A[4] D[4] A[3] D[3] A[2] VSSIO D[2] A[1] D[1] A[0] D[0] VSSCORE VDDCORE VSSIO VDDIO CL[2] CL[1] FRM M DD[3] DD[2] VSSIO DD[1] DD[0] NRAS[1] NRAS[0] NCAS[3] NCAS[2] VDDIO VSSIO NCAS[1] NCAS[0] NMWE NMOE VSSIO NCS[0] NCS[1] NCS[2] NCS[3] NCS[4]

Notes:

1) For package specifications, please see 208--Pin LQFP Package Outline Drawing on page 125 2) N/C should not be grounded but left as no connects Figure 1. 208-Pin LQFP (Low Profile Quad Flat Pack) Pin Diagram

DS474PP1

EP7212 2.2

Pin Descriptions

Table 4 describes the function of all the external signals to the EP7212. Note that all output signals and all I/O pins (when acting as outputs) are three stateable. This is to enable the Hi-Z test modes to be supported.

2.2.1

External Signal Functions

Function

Signal Name

Signal

Data bus

D[0-31]

I/O

A[0-14]

Address bus

A[15-27] DRA[0-12]

Memory Interface

Description 32-bit system data bus for memory, DRAM, and I/O interface 15 bits of system byte address during memory and expansion cycles DRA[0-12] is multiplexed with A[15-27], offering additional power savings since the lightest loading is expected on the high order ROM address lines. Whenever the EP7212 is in the Standby State, the external address and data buses are driven low. The RUN signal is used internally to force these buses to be driven low. This is done to prevent peripherals that are powered-down from draining current. Also, the internal peripheralâ&#x20AC;&#x2122;s signals get set to their Reset State.

nRAS[0-1]

Row Address Select outputs to DRAM banks 0 to 1.

nCAS[0-3]

I/O

Column Address Select outputs allowing for bytes 0 to 3 within a 32-bit word.

nMOE

Memory output enable

nMWE

Memory write enable

nCS[0-3]

Chip select; active low, SRAM-like chip selects for expansion

nCS[4-5]

Chip select; active low, CS for expansion or for CL-PS6700 select

EXPRDY

Expansion port ready; external expansion devices drive this low to extend the bus cycle. This is used to insert wait states for an external bus cycle.

WRITE

Write strobe, low during reads, high during writes from the EP7212

WORD/ HALFWORD

To do write accesses of different sizes Word and Half-Word must be externally decoded. The encoding of these signals is as follows:

Access Size Word Half-Word Byte

Word 1 * 0

Half-Word 0 1 0

The core will generate an address. When doing a read, the ARM core will select the appropriate byte channels. When doing a write, the correct bytes will have to be enabled depending on the above signals and the least significant bits of the address bus. The ARM architecture does not support unaligned accesses. For a read using x 32 memory, it is assumed that you will ignore bits 1 and 0 of the address bus and perform a word read (or in power critical systems decode the relevant bits depending on the size of the access). If an unaligned read takes place, the core will rotate the resulting data in the register. For more information on this behavior see the LDR instruction in the ARM7TDMI data sheet. EXPCLK

I/O

Expansion clock rate is the same as the CPU clock for 13 MHz and 18 MHz. It runs at 36.864 MHz for 36,49 and 74 MHz modes; in 13 MHz mode this pin is used as the clock input.

Table 4. External Signal Functions

DS474PP1

EP7212 Function

Interrupts

Power Management

Signal Name

Signal

Description

nMEDCHG/ nBROM

Media changed input; active low, deglitched. Used as a general purpose FIQ interrupt during normal operation. It is also used on power up to configure the processor to either boot from the internal Boot ROM, or from external memory. When low, the chip will boot from the internal Boot ROM.

nEXTFIQ

External active low fast interrupt request input

EINT[3]

External active high interrupt request input

nEINT[1:2]

Two general purpose, active low interrupt inputs

nPWRFL1

Power fail input; active low, deglitched input to force system into the Standby State

BATOK1

Main battery OK input; falling edge generates a FIQ, a low level in the Standby State inhibits system start up; deglitched input

nEXTPWR

External power sense; must be driven low if the system is powered by an external source

nBATCHG1

New battery sense; driven low if battery voltage falls below the "no-battery" threshold; it is a deglitched input

nPOR

Power-on reset input. This signal is not deglitched. When active it completely resets the entire system, including all the RTC registers. Upon power-up, the signal must be held active low for a minimum of 100 Âľsec after VDD has settled. During normal operation, nPOR needs to be held low for at least one clock cycle of the selected clock speed (i.e., when running at 13 MHz, the pulse width of nPOR needs to be > 77 nsec).

State Control Note that nURESET, RUN/CLKEN, TEST(0), TEST(1), PE(0), PE(1), PE(2), DRIVE(0), DRIVE(1), DD(0), DD(1), DD(2), and DD(3) are all latched on the rising edge of nPOR. RUN/CLKEN

I/O

This pin is programmed to either output the RUN signal or the CLKEN signal. The CLKENSL bit is used to configure this pin. When RUN is selected, the pin will be high when the system is active or idle, low while in the Standby State. When CLKEN is selected, the pin will only be driven low when in the Standby State (For RUN, see Table 6).

WAKEUP1

Wake up is a deglitched input signal. It must also be held high for at least 125 Âľsec to guarantee its detection. Once detected it forces the system into the Operating State from the Standby State. It is only active when the system is in the Standby State. This pin is ignored when the system is in the Idle or Operating State. It is used to wakeup the system after first power-up, or after software has forced the system into the Standby State. WAKEUP will be ignored for up to two seconds after nPOR goes HIGH. Therefore, the external WAKEUP logic must be designed to allow it to rise and stay HIGH for at least 125 usec, two seconds after nPOR goes HIGH.

nURESET1

User reset input; active low deglitched input from user reset button. This pin is also latched upon the rising edge of nPOR and read along with the input pins nTEST[0-1] to force the device into special test modes. nURESET does not reset the RTC.

Table 4. External Signal Functions (cont.)

DS474PP1

EP7212 Function

DAI, Codec or SSI2 Interface (See Table 5 for pin assignment and direction following multiplexing)

ADC Interface (SSI1)

IrDA and RS232 Interfaces

LCD

Keyboard & Buzzer drive LED Flasher

Signal Name

Signal

Description

SSICLK

I/O

DAI/Codec/SSI2 clock signal

SSITXFR

I/O

DAI/Codec/SSI2 serial data output frame/synchronization pulse output

SSITXDA

DAI/Codec/SSI2 serial data output

SSIRXDA

DAI/Codec/SSI2 serial data input

SSIRXFR

I/O

SSI2 serial data input frame/synchronization pulse DAI external clock input

ADCCLK

Serial clock output

nADCCS

Chip select for ADC interface

ADCOUT

Serial data output

ADCIN

Serial data input

SMPCLK

Sample clock output

LEDDRV

Infrared LED drive output (UART1)

PHDIN

Photo diode input (UART1)

TXD[1-2]

RS232 UART1 and 2 TX outputs

RXD[1-2]

RS232 UART1 and 2 RX inputs

DSR

RS232 DSR input

DCD

RS232 DCD input

CTS

RS232 CTS input

DD[0-3]

I/O

LCD serial display data; pins can be used on power up to read the ID of some LCD modules (See Table 6).

CL[1]

LCD line clock

CL[2]

LCD pixel clock

FRM

LCD frame synchronization pulse output

LCD AC bias drive

COL[0-7]

Keyboard column drives (SYSCON1)

BUZ

Buzzer drive output (SYSCON1)

PD[0]/ LEDFLSH

LED flasher driver â&#x20AC;&#x201D; multiplexed with Port D bit 0. This pin can provide up to 4 mA of drive current.

Table 4. External Signal Functions (cont.)

DS474PP1

EP7212 Function

General Purpose I/O

Signal Name

Signal

PA[0:7]

I/O

Port A I/O (bit 6 for boot clock option, bit 7 for CL-PS6700 PRDY input); also used as keyboard row inputs

PB[0]/PRDY1 PB[1]/PRDY2 PB[2:7]

I/O

Port B I/O. All eight Port B bits can be used as GPIOs. When the PC CARD1 or 2 control bits in the SYSCON2 register are deasserted, PB[0] and PB[1] are available for GPIO. When asserted, these port bits are used as the PRDY signals for connected CL-PS6700 PC Card Host Adapter devices.

PD[0:7]

I/O

Port D I/O

PE[0]/ BOOTSEL[0]

I/O

Port E I/O (3 bits only). Can be used as general purpose I/O during normal operation.

PE[1]/ BOOTSEL[1]

I/O

During power-on reset, PE[0] and PE[1] are inputs and are latched by the rising edge of nPOR to select the memory width that the EP7212 will use to read from the boot code storage device (i.e., external 8-bit-wide FLASH bank).

PE[2]/ CLKSEL

I/O

During power-on reset, PE[2] is latched by the rising edge of nPOR to select the clock mode of operation (i.e., either the PLL or external 13 MHz clock mode).

DRIVE[0:1]

I/O

PWM drive outputs. These pins are inputs on power up to determine what polarity the output of the PWM should be when active. Otherwise, these pins are always an output (See Table 6).

FB[0:1]

PWM feedback inputs

PWM Drives

Description

TDI

JTAG data in

TDO

JTAG data out

Boundary Scan

TMS

JTAG mode select

TCLK

JTAG clock

nTRST

JTAG async reset

Test

nTEST[0:1]

Test mode select inputs. These pins are used in conjunction with the power-on latched state of nURESET to select between the various device test models.

MOSCIN MOSCOUT

I O

Main 3.6864 MHz oscillator for 18.432 MHz–73.728 MHz PLL

RTCIN RTCOUT

I O

Real Time Clock 32.768 kHz oscillator

Oscillators

No Connects

N/C

No connects should be left as no connects; do not connect to ground

Table 4. External Signal Functions (cont.) 1. All deglitched inputs are via the 16.384 kHz clock. Each deglitched signal must be held active for at least two clock periods. Therefore, the input signal must be active for at least ~125 µs to be detected cleanly.

The RTC crystal must be populated for the device to function properly.

DS474PP1

EP7212 2.2.2

SSI/Codec/DAI Pin Multiplexing SSI2

Codec

DAI

Direction

Strength

SSICLK

PCMCLK

SCLK

I/O

SSITXFR

PCMSYNC

LRCK

I/O

1 1

SSITXDA

PCMOUT

SDOUT

Output

SSIRXDA

PCMIN

SDIN

Input

SSIRXFR

p/u*

MCLK

I/O

p/u = use an ~10 k pull-up

The selection between SSI2 and the codec is controlled by the state of the SERSEL bit in SYSCON2 (See SYSCON2 System Control Register 2). The choice between the SSI2, codec, and the DAI is controlled by the DAISEL bit in SYSCON3 (See SYSCON3 System Control Register 3). Table 5. SSI/Codec/DAI Pin Multiplexing

2.2.3

Output Bi-Directional Pins

RUN

The RUN pin is looped back in to skew the address and data bus from each other.

nCAS[3:0]

The nCAS pins are looped back into the EP7212 to be used as the actual clock source for the data to be latched internally.

Drive [0-1]

Drive 0 and 1 are looped back in on power up to determine what polarity the output of the PWM should be when active.

DD[3:0]

DD[3:0] are looped back in on power up to enable the reading of the ID of some LCD modules.

NOTE:

The above output pins are implemented as bi-directional pins to enable the output side of the pad to be monitored and hence provide more accurate control of timing or duration. Table 6. Output Bi-Directional Pins

DS474PP1

EP7212 3. FUNCTIONAL DESCRIPTION

•

Interrupt controller

The EP7212 device is a single-chip embedded controller designed to be used in low-cost and ultralow-power applications. Operating at 74 MHz, the EP7212 delivers approximately 66 Dhrystone 2.1 MIPS of sustained performance (74 MIPS peak). This is approximately the same as a 100 MHz Pentium-based PC.

•

Advanced system state control and power management.

•

Two full-duplex 16550A compatible UARTs with 16-byte transmit and receive FIFOs.

•

IrDA SIR protocol controller capable of speeds up to 115.2 kbps.

The EP7212 contains the following functional blocks:

•

Programmable 1-, 2-, or 4-bit-per-pixel LCD controller with 16-level grayscaler.

•

Programmable frame buffer start address, allowing a system to be built using only internal SRAM for memory.

•

On-chip boot ROM programmed with serial load boot sequence.

•

Two 16-bit general purpose timer counters.

•

A 32-bit Real Time Clock (RTC) and comparator.

•

Dedicated LED flasher pin driven from the RTC with programmable duty ratio (multiplexed with a GPIO pin).

•

Two synchronous serial interfaces for Microwire or SPI peripherals such as ADCs, one supporting both the master and slave mode and the other supporting only the master mode.

•

Full JTAG boundary scan and Embedded ICE support.

•

Two programmable pulse-width modulation interfaces.

•

An interface to one or two Cirrus Logic CLPS6700 PC Card controller devices to support two PC Card slots.

•

EDO DRAM support (Fast Page DRAM is only supported at 13 MHz and 18 MHz. It can interface up to two banks of DRAM. Each bank can be up to 256 Mbytes in size. The DRAM interface is programmable to be 16-bit or 32-bit wide.

ARM720T processor which consists of the following functional sub-blocks: -

ARM7TDMI CPU core (which supports the logic for the Thumb instruction set, core debug, enhanced multiplier, JTAG, and the Embedded ICE) running at a dynamically programmable clock speed of 18 MHz, 36 MHz, 49 MHz, or 74 MHz. Memory Management Unit (MMU) compatible with the ARM710 core (providing address translation and a 64-entry translation lookaside buffer) with added support for Windows CE.

8 kbytes of unified instruction and data cache with a four-way set associative cache controller.

Write buffer

•

38,400 bytes (0x9600) of on-chip SRAM that can be shared between the LCD controller and general application use.

•

Memory interfaces for up to 6 independent 256 Mbyte expansion segments with programming wait states.

•

27 bits of general purpose I/O - multiplexed to provide additional functionality where necessary.

•

Digital Audio Interface (DAI) for connection to CD-quality DACs and codecs.

DS474PP1

EP7212 •

3.1

Oscillator and phase-locked loop (PLL) to generate the core clock speeds of 18.432 MHz, 36.864 MHz, 49.152 MHz, and 73.728 MHz from an external 3.6864 MHz crystal, with an alternative external clock input (used in 13 MHz mode).

•

CPU Core

The ARM720T consists of an ARM7TDMI 32-bit RISC processor, a unified cache, and a memory management unit (MMU). The cache is four-way set associative with 8-kbytes organized as 512 lines of 4 words. The cache is directly connected to the ARM7TDMI, and therefore caches the virtual address from the CPU. When the cache misses, the MMU translates the virtual address into a physical address. A 64-entry translation lookaside buffer (TLB) is utilized to speed the address translation process and reduce bus traffic necessary to read the page table. The MMU saves power by only translating the cache misses.

A low power 32.768 kHz oscillator.

The EP7212 design is optimized for low power dissipation and is fabricated on a fully static 0.25 micron CMOS process. It is available in a 256-ball PBGA or a 208-pin LQFP package. Figure 2 shows a simplified block diagram of the EP7212. All external memory and peripheral devices are connected to the 32-bit data bus using the external 28-bit address bus and control signals.

See the ARM720T Data sheet for a complete description of the various logic blocks that make up the processor, as well as all internal register information.

13-MHZ INPUT INTERNAL DATA BUS

3.6864 MHZ

PLL

32.768 KHZ

32.768-KHZ OSCILLATOR

D[0-31]

ARM720T

NPOR, RUN, RESET, WAKEUP

STATE CONTROL

BATOK, EXTPWR PWRFL, BATCHG

POWER MANAGEMENT

EINT[1-3], FIQ, MEDCHG

INTERRUPT CONTROLLER

FLASHING LED DRIVE PORTS A, B, D (8-BIT) PORT E (3-BIT) KEYBD DRIVERS (0–7) BUZZER DRIVE DC-TO-DC ADCCLK, ADCIN, ADCOUT, SMPCLK, ADCCS SSICLK, SSITXFR, SSITXDA, SSIRXDA, SSIRSFR

ARM7TDMI CPU CORE

MEMORY CONTROLLER CL-PS6700 INTFC.

8-KBYTE CACHE

EXPCLK, WORD, NCS[0:3], EXPRDY, WRITE MOE, MWE, NRAS[0-1], NCAS[0-3]

EXPANSION CONTROL

MMU

DRAM CNTRL

WRITE BUFFER

RTC

INTERNAL ADDRESS BUS

A[0-27], DRA[0-12]

LCD DMA

GPIO

TIMER COUNTERS (2)

PWM ON-CHIP BOOT ROM

SSI1 (ADC) DAI SSI2 CODEC

ICE-JTAG LCD CONTROLLER ON-CHIP SRAM 38,400 BYTES

EPB BRIDGE EPB BUS

PB[0:1], NCS[4:5]

TEST AND DEVELOPMENT LCD DRIVE

IrDA

LED AND PHOTODIODE

UART1

ASYNC INTERFACE 1

UART2

ASYNC INTERFACE 2

Figure 2. EP7212 Block Diagram

DS474PP1

EP7212 3.2

State Control

3.2.1

The EP7212 supports the following Power Management States: Operating, Idle, and Standby (see Figure 3). The normal program execution state is the Operating State; this is a full performance state where all of the clocks and peripheral logic are enabled. The Idle State is the same as the Operating State with the exception of the CPU clock being halted, and an interrupt or wakeup will return it back to the Operating State. The Standby State has the lowest power consumption of the three states. By selecting this mode the main oscillator shuts down, leaving only the Real Time Clock and its associated logic powered. It is important when the EP7212 is in Standby that all power and ground pins remain connected to power and ground in order to have a proper system wake-up. The only state that Standby can transition to is the Operating State. Interrupt or rising wakeup

Standby

Operating Write to standby location, power fail, or user reset pt rru te n I

nPOR, power fail, or user reset

Write to halt location

Idle

Figure 3. State Diagram

In the description below, the RUN/CLKEN pin can be used either for the RUN functionality, or the CLKEN functionality to allow an external oscillator to be disabled in the 13 MHz mode. Either RUN or CLKEN functionality can be selected according to the state of the CLKENSL bit in the SYSCON2 register. Table 7 on the following page shows peripheral status in various power management states.

Standby State

The Standby State equates to the system being switched "off" (i.e., no display, and the main oscillator is shut down). When the 18.432â&#x20AC;&#x201C;73.72 MHz mode is selected, the PLL will be shut down. In the 13 MHz mode, if the CLKENSL bit is set low, then the CLKEN signal will be forced low and can, if required, be used to disable an external oscillator. In the Standby State, all the system memory and state is maintained and the system time is kept upto-date. The PLL/on-chip oscillator or external oscillator is disabled and the system is static, except for the low power watch crystal (32 kHz) oscillator and divider chain to the RTC and LED flasher. The RUN signal is driven low, therefore this signal can be used externally in the system to power down other system modules. Whenever the EP7212 is in the Standby State, the external address and data buses are forced low internally by the RUN signal. This is done to prevent peripherals that are powered down from draining current. Also, the internal peripheralâ&#x20AC;&#x2122;s signals get set to their Reset State. When first powered, or reset by the nPOR (Power On Reset, active low) signal, the EP7212 is forced into the Standby State. This is known as a cold reset, and when leaving the Standby State after a cold reset, external wake up is the only way to wake up the device. When leaving the Standby State after non-cold reset conditions (i.e., the software has forced the device into the Standby State), the transition to the Operating State can be caused by a rising edge on the WAKEUP input signal or by an enabled interrupt. Normally, when entering the Standby State from the Operating State, the software will leave some interrupt sources enabled. NOTE:

The CPU cannot be awakened by the TINT, WEINT, and BLINT interrupts when in the Standby State.

Typically, software writes to the Standby internal memory location to cause the transition from the DS474PP1

EP7212 Address (W/B)

Operating

Idle

Standby

nPOR RESET

nURESET RESET

DRAM Control

SELFREF

Off

SELFREF

UARTs

Off

Reset

LCD FIFO

Reset

LCD

Off

Reset

ADC Interface

Off

Reset

SSI2 Interface

Off

Reset

DAI Interface

Off

Reset

Codec

Off

Reset

Timers

Off

Reset

RTC

LED Flasher

Reset

DC-to-DC

Off

Reset

CPU

Off

Reset

Interrupt Control

Reset

PLL/CLKEN Signal

Off

Table 7. Peripheral Status in Different Power Management States

Operating State to the Standby State. Before entering the Standby State, if external I/O devices (such as the CL-PS6700s connected to nCS[4] or nCS[5]) are in use, the software must check to ensure that they are idle before issuing the write to the Standby State location. Before entering the Standby State, the software must properly disable the DAI. Failing to do so will result in higher than expected power consumption in the Standby State, as well as unpredictable operation of the DAI. The DAI can be re-enabled after transitioning back to the Operating State. The system can also be forced into the Standby State by hardware if the nPWRFL or nURESET inputs are forced low. The only exit from the Standby State is to the Operating State. The system will only transition to the Operating State from the Standby State under the following conditions: when the nPWRFL input pin is high when the nEXTPWR input pin is low or when the BATOK input pin is high. This prevents the system

from starting when the power supply is inadequate (i.e., the main batteries are low), corresponding to a low level on nPWRFL or BATOK. From the Standby State, if the WAKEUP signal is applied with no clock except the 32 kHz clock running, the EP7212 will be initialized into a state where it is ready to start and is waiting for the CPU to start receiving its clock. The CPU will still be held in reset at this point. After the first clock is applied, there will be a delay of about eight clock cycles before the CPU is enabled. This delay is to allow the clock to the CPU time to settle.

3.2.1.1

UART in Standby State

During the Standby State, the UARTs are disabled and cannot detect any activity (i.e., start bit) on the receiver. If this functionality is required then this can be accomplished in software by the following method: 1) Permanently connect the RX pin to one of the active low external interrupt pins.

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EP7212 power saving state only if the keyboard interrupt is non-masked (i.e., the interrupt mask register 2 (INTMR2 bit 0) is high).

2) Ensure that on entry to the Standby State, the chosen interrupt source is not masked, and the UART is enabled. 3) Send a preamble that consists of one start bit, 8 bits of zero, and one stop bit. This will cause the EP7212 to wake and execute the enabled interrupt vector. The UART will automatically be re-enabled when the processor re-enters the Operating State, and the preamble will be received. Since the UART was not awake at the start of the preamble, the timing of the sample point will be off-center during the preamble byte. However, the next byte transmitted will be correctly aligned. Thus, the actual first real byte to be received by the UART will get captured correctly.

3.2.2

In the Idle State, the device functions just like it does when in the Operating State. However, the CPU clock is halted while it waits for an event such as a key press to generate an interrupt. The PLL (in 18.432–73.728 MHz mode) or the external 13 MHz clock source always remains active in the Idle State.

Keyboard Interrupt

For the case of the keyboard interrupt, the following options are available and are selectable according to bits 1 and 3 of the SYSCON2 register (refer to the SYSCON2 Register Description for details). •

When KBWEN is high, a keypress will cause the device to wake up regardless of the state of the interrupt mask register. This is called the “Keyboard Direct Wakeup’ mode. In this mode, the interrupt request may not get serviced. If the interrupt is masked (i.e., the interrupt mask register 2 (INTMR2 bit 0) is low), the processor simply starts re-executing code from where it left off before it entered the power saving state. If the interrupt is non-masked, then the processor will service the interrupt.

•

When the KBD6 bit (SYSCON2 bit 1) is low, all 8 of Port A inputs are OR’ed together to produce the internal wakeup signal and keyboard interrupt request. This is the default reset state.

•

When the KBD6 bit (SYSCON2 bit 1) is high, only the lowest 6 bits of Port A are OR’ed together to produce the internal wakeup signal and keyboard interrupt request. The two most significant bits of Port A are available as GPIO when this bit is set high.

Idle State

If in the Operating State, the Idle State can be entered by writing to a special internal memory location (HALT) in the EP7212. If an interrupt occurs, the EP7212 will return immediately back to the Operating State and execute the next instruction. The WAKEUP signal can not be used to exit the Idle State. It is only used to exit the Standby State.

3.2.3

•

If the KBWEN bit (SYSCON2 bit 3) is set low, then a keypress will cause a transition from a

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In the case where KBWEN is low and the INTMR2 bit 0 is low, it will only be possible to wakeup the device by using the external WAKEUP pin or another enabled interrupt source. The keyboard interrupt capability allows an OS to use either a polled or interrupt-driven keyboard routine, or a combination of both. NOTE:

3.3

The keyboard interrupt is NOT deglitched.

Power-Up Sequence

The EP7212 has a power-up sequence that should be followed for proper start up. If any of the below recommended timing sequences are violated, then it is possible that the part may not start-up properly. This could cause the device to get lost and not recover without a hard reset.

EP7212 1). Upon power, the signal nPOR must be held active (LOW) for a minimum of 100us, after VDD has become settled. 2). After nPOR goes HIGH, the EP7212 will enter the Standby State (and only this state). In this state, the PLL is not enabled, and thus the CPU is not enabled either. The only method that can be used to allow the EP7212 to exit the Standby State into the Operating State is by the WAKEUP signal going active (HIGH). NOTE:

It is not a requirement to use the nURESET signal. If not used, the nURESET signal must be HIGH, and it must have gone HIGH prior to nPOR going HIGH. This is due to the fact that nURESET is latched into the device by the rising edge of nPOR. When nURESET is LOW on the rising edge of nPOR, it can force the device into one of its Test Mode states.

3). After nPOR goes HIGH, the WAKEUP signal cannot be detected as going HIGH, until after at least two seconds. After two seconds, the WAKEUP signal can become active, and it must be HIGH for at least 125us. 4). After the WAKEUP signal is detected internally, it first goes through a deglitching circuit. This is why is must be active for at least 125us. Then the PLL gets enabled. WAKEUP is ignored immediately after waking up the system. It also ignores it while in the Idle or Operating State. It can constantly toggle with no affect on the device. It will only be read again if nPOR goes low and then high again, or if software has forced the device back into the Standby State. 5). A maximum of 250 msec will pass before the CPU becomes enabled and starts to fetch the first instruction.

3.4

Resets

There are three asynchronous resets to the EP7212: nPOR, nPWRFL and nURESET. If any of these are active, a system reset is generated internally. This will reset all internal registers in the EP7212 except

the RTC data and match registers. These registers are only cleared by nPOR allowing the system time to be preserved through a user reset or power fail condition. Any reset will also reset the CPU and cause it to start execution at the reset vector when the EP7212 returns to the Operating State. Internal to the EP7212, three different signals are used to reset storage elements. These are nPOR, nSYSRES and nSTBY. nPOR is an external signal. nSTBY is equivalent to the external RUN signal. nPOR (Power On Reset, active low) is the highest priority reset signal. When active (low), it will reset all storage elements in the EP7212. nPOR active forces nSYSRES and nSTBY active. nPOR will only be active after the EP7212 is first powered up and not during any other resets. nPOR active will clear all flags in the status register except for the cold reset flag (CLDFLG) bit (SYSFLG, bit 15), which is set. nSYSRES (System Reset, active low) is generated internally to the EP7212 if nPOR, nPWRFL, or nURESET are active. It is the second highest priority reset signal, used to asynchronously reset most internal registers in the EP7212. nSYSRES active forces nSTBY and RUN low. nSYSRES is used to reset the EP7212 and force it into the Standby State with no co-operation from software. The CPU is also reset. The nSTBY and RUN signals are high when the EP7212 is in the Operating or Idle States and low when in the Standby State. The main system clock is valid when nSTBY is high. The nSTBY signal will disable any peripheral block that is clocked from the master clock source (i.e., everything except for the RTC). In general, a system reset will clear all registers and nSTBY will disable all peripherals that require a main clock. The following peripherals are always disabled by a low level on nSTBY: two UARTs and IrDA SIR encoder, timer counters, telephony codec, and the two SSI interDS474PP1

EP7212 faces. In addition, when in the Standby State, the LCD controller and PWM drive are also disabled. When operating from an external 13 MHz oscillator which has become disabled in the Standby State by using the CLKEN (SYSCON, bit 13) signal (i.e., with CLKENSL = 0), the oscillator must be stable within 0.125 sec from the rising edge of the CLKEN signal.

3.5

Clocks

There are two clocking modes for the EP7212. Either an external clock input can be used or the onchip PLL. The clock source is selected by a strapping option on Port E, pin 2 (PE[2]). If PE[2] is high at the rising edge of nPOR (i.e., upon powerup), the external clock mode is selected. If PE[2] is low, then the on-chip PLL mode is selected. After power-up, PE[2] can be used as a GPIO. The EP7212 device contains several separate sections of logic, each clocked according to its own clock frequency requirements. When the EP7212 is in external clock mode, the actual frequencies at the peripherals will be different than when in PLL mode. See each peripheral device section for more details. The section below describes the clocking for both the ARM720T and address/data bus.

3.5.1

ARM720T gets clocked at this higher speed. The address/data will be fixed at 36 MHz. The clock frequency used is selected by programming the CLKCTL[1:0] bits in the SYSCON3 register. The clock frequency selection does not effect the EPB (external peripheral bus). Therefore, all the peripheral clocks are fixed, regardless of the clock speed selected for the ARM720T. NOTE:

After modifying the CLKCTL[1:0] bits, the next instruction should always be a ‘NOP’.

3.5.1.1

Characteristics of the PLL Interface

When connecting a crystal to the on-chip PLL interface pins (i.e. MOSCIN and MOSCOUT), the crystal and circuit should conform to the following requirements: •

The 3.6864 MHz frequency should be created by the crystals fundamental tone (i.e., it should be a fundamental mode crystal).

•

A start-up resistor is not necessary, since one is provided internally.

•

Start-up loading capacitors may be placed on each side of the external crystal and ground. Their value should be in the range of 10 pF. However, their values should be selected based upon the crystal specifications. The total sum of the capacitance of the traces between the EP7212’s clock pins, the capacitors, and the crystal leads should be subtracted from the crystal’s specifications when determining the values for the loading capacitors.

•

The crystal should have a maximum 100 ppm frequency drift over the chip’s operating temperature range.

On-Chip PLL

The ARM720T clock can be programmed to 18.432 MHz, 36.864 MHz, 49.152 MHz, or 73.728 MHz with the PLL running at twice the highest possible CPU clock frequency (147.456 MHz). The PLL uses an external 3.6864 MHz crystal. By chip default, the on-chip PLL is used and configured such that the ARM720T and address/data buses run at 18.432 MHz. When the clock frequency is selected to be 36 MHz, both the ARM720T and the address/data buses are clocked at 36 MHz. When the clock frequency is selected higher than 36 MHz, only the

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Alternatively, a digital clock source can be used to drive the MOSCIN pin of the EP7212. With this approach, the voltage levels of the clock source should match that of the VDD supply for the EP7212’s pads (i.e. the supply voltage level used to drive all of the non-VDD core pins on the EP7212).

EP7212 The output clock pin (i.e., MOSCOUT) should be left floating.

3.5.2

External Clock Input (13 MHz)

An external 13 MHz crystal oscillator can be used to drive all of the EP7212. When selected the ARM720T and the address/data buses both get clocked at 13 MHz. The fixed clock sources to the various peripherals will have different frequencies than in the PLL mode. In this configuration, the PLL will not be used at all. NOTE:

When operating at 13 MHz, the CLKCTL[1:0] bits should not be changed from their default value of â&#x20AC;&#x2DC;00â&#x20AC;&#x2122;.

3.5.3 Dynamic Clock Switching When in the PLL Clocking Mode The clock frequency used for the CPU and the buses is controlled by programming the CLKCTL[1:0] bits in the SYSCON3 register. When this occurs, the state controller switches from the current to the new clock frequency as soon as possible without causing a glitch on the clock signals. The glitchfree clock switching logic waits until the clock that is currently in use and the newly programmed clock source are both low, and then switches from the previous clock to the new clock without a glitch on the clocks.

13 MHz

CLKEN

Figure 4. CLKEN Timing Entering the Standby State

EXPCLK (internal) RUN CLKEN Interrupt / WAKEUP

Figure 5. CLKEN Timing Entering the Standby State

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EP7212 3.6

Interrupt Controller

When unexpected events arise during the execution of a program (i.e., interrupt or memory fault) an exception is usually generated. When these exceptions occur at the same time, a fixed priority system determines the order in which they are handled. Table 8 shows the priority order of all the exceptions. Priority

Exception

Highest

Reset

Data Abort

FIQ

IRQ

Prefetch Abort

Lowest

Undefined Instruction, Software Interrupt

Table 8. Exception Priority Handling

The EP7212 interrupt controller has two interrupt types: interrupt request (IRQ) and fast interrupt request (FIQ). The interrupt controller has the ability to control interrupts from 22 different FIQ and IRQ sources. Of these, seventeen are mapped to the IRQ input and five sources are mapped to the FIQ input. FIQs have a higher priority than IRQs. If two interrupts are received from within the same group (IRQ or FIQ), the order in which they are serviced must be resolved in software. The priorities are listed in Table 9. All interrupts are level sensitive; that is, they must conform to the following sequence. 1) The interrupting device (either external or internal) asserts the appropriate interrupt. 2) If the appropriate bit is set in the interrupt mask register, then either a FIQ or an IRQ will be asserted by the interrupt controller. (A description for each bit in this register can be found in INTSR1 Interrupt Status Register 1). 3) If interrupts are enabled the processor will jump to the appropriate address. 4) Interrupt dispatch software reads the interrupt DS474PP1

status register to establish the source(s) of the interrupt and calls the appropriate interrupt service routine(s). 5) Software in the interrupt service routine will clear the interrupt source by some action specific to the device requesting the interrupt (i.e., reading the UART RX register). The interrupt service routine may then re-enable interrupts, and any other pending interrupts will be serviced in a similar way. Alternately, it may return to the interrupt dispatch code, which can check for any more pending interrupts and dispatch them accordingly. The “End of Interrupt” type interrupts are latched. All other interrupt sources (i.e., external interrupt source) must be held active until its respective service routine starts executing. See “End Of Interrupt Locations” on page 83 for more details. Table 9, Table 10, and Table 11 show the names and allocation of interrupts in the EP7212.

3.6.1 3.6.1.1

Interrupt Latencies in Different States Operating State

The ARM720T processor checks for a low level on its FIQ and IRQ inputs at the end of each instruction. The interrupt latency is therefore directly related to the amount of time it takes to complete execution of the current instruction when the interrupt condition is detected. First, there is a one to two clock cycle synchronization penalty. For the case where the EP7212 is operating at 13 MHz with a 16-bit external memory system, and instruction sequence stored in one wait state FLASH memory, the worst-case interrupt latency is 251 clock cycles. This includes a delay for cache line fills for instruction prefetches, and a data abort occurring at the end of the LDM instruction, and the LDM being non-quad word aligned. In addition, the worst-case interrupt latency assumes that LCD DMA cycles to support a panel size of 320 x 27

EP7212

Interrupt

Bit in INTMR1 and INTSR1

Name

Comment

FIQ

EXTFIQ

FIQ

BLINT

FIQ

WEINT

Tick Watchdog expired interrupt

FIQ

MCINT

Media changed interrupt

IRQ

CSINT

Codec sound interrupt

IRQ

EINT1

External interrupt input 1 (nEINT[1] pin)

External fast interrupt input (nEXTFIQ pin) Battery low interrupt

IRQ

EINT2

External interrupt input 2 (nEINT[2] pin)

IRQ

EINT3

External interrupt input 3 (EINT[3] pin)

IRQ

TC1OI

TC1 underflow interrupt

IRQ

TC2OI

TC2 underflow interrupt

IRQ

RTCMI

IRQ

TINT

IRQ

UTXINT1

Internal UART1 transmit FIFO empty interrupt

IRQ

URXINT1

Internal UART1 receive FIFO full interrupt

IRQ

UMSINT

Internal UART1 modem status changed interrupt

IRQ

SSEOTI

Synchronous serial interface 1 end of transfer interrupt

RTC compare match interrupt 64 Hz tick interrupt

Table 9. Interrupt Allocation in the First Interrupt Register

Interrupt

Bit in INTMR2 and INTSR2

Name

IRQ

KBDINT

Key press interrupt

IRQ

SS2RX

Master / slave SSI 16 bytes received

IRQ

SS2TX

Master / slave SSI 16 bytes transmitted

IRQ

UTXINT2

UART2 transmit FIFO empty interrupt

IRQ

URXINT2

UART2 receive FIFO full interrupt

Comment

Table 10. Interrupt Allocation in the Second Interrupt Register

Interrupt

Bit in INTMR3 and INTSR3

Name

FIQ

DAIINT

Comment DAI interface interrupt

Table 11. Interrupt Allocation in the Third Interrupt Register

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EP7212 240 at 4 bits-per-pixel, 60 Hz refresh rate, is in progress. This would give a worst-case interrupt latency of about 19.3 µs for the ARM720T processor operating at 13 MHz in this system. For those interrupt inputs which have de-glitching, this figure is increased by the maximum time required to pass through the deglitcher, which is approximately 125 µs (2 cycle of the 16.384 kHz clock derived from the RTC oscillator). This would create an absolute worst-case latency of approximately 141 µs. If the ARM720T is run at 36 MHz or greater and/or 32 bit wide external memory, the 19.3 µs value will be reduced. All the serial data transfer peripherals included in the EP7212 (except for the master-only SSI1) have local buffering to ensure a reasonable interrupt latency response requirement for the OS of 1 ms or less. This assumes that the design data rates do not exceed the data rates described in this specification. If the OS cannot meet this requirement, there will be a risk of data over/underflow occurring.

3.6.1.2

Idle State

When leaving the Idle State as a result of an interrupt, the CPU clock is restarted after approximately two clock cycles. However, there is still potentially up to 20 µsec latency as described in the first section above, unless the code is written to include at least two single cycle instructions immediately after the write to the IDLE register (in which case the latency drops to a few microseconds). This is important, as the Idle State can only be left because of a pending interrupt, which has to be synchronized by the processor before it can be serviced.

3.6.1.3

Standby State

In the Standby State, the latency will depend on whether the system clock is shut down and if the FASTWAKE bit in the SYSCON3 register is set. If the system is configured to run from the internal PLL clock, then the PLL will always be shut down DS474PP1

when in the Standby State. In this case, if the FASTWAKE bit is cleared, then there will be a latency of between 0.125 sec to 0.25 sec. If the FASTWAKE bit is set, then there will be a latency of between 250 µsec to 500 µsec. If the system is running from the external clock (at 13 MHz), with the CLKENSL bit in SYSCON2 set to 0, then the latency will also be between 0.125 sec and 0.25 sec to allow an external oscillator to stabilize. In the case of a 13 MHz system where the clock is not disabled during the Standby State (CLKENSL = 1), then the latency will be the same as described in the Idle State section above. Whenever the EP7212 is in the Standby State, the external address and data buses are driven low. The RUN signal is used internally to force these buses to be driven low. This is done to prevent peripherals that are power-down from draining current. Also, the internal peripheral’s signals get set to their Reset State. Table 12 summarizes the five external interrupt sources and the effect they have on the processor interrupts.

3.7

EP7212 Boot ROM

The 128 bytes of on-chip Boot ROM contain an instruction sequence that initializes the device and then configures UART1 to receive 2048 bytes of serial data that will then be placed in the on-chip SRAM. Once the download is complete, execution jumps to the start of the on-chip SRAM. This would allow, for example, code to be downloaded to program system FLASH during a product’s manufacturing process. See Appendix A: Boot Code for details of the ROM Boot Code with comments to describe the stages of execution. Selection of the Boot ROM option is determined by the state of the nMEDCHG pin during a power on reset. If nMEDCHG is high while nPOR is active, then the EP7212 will boot from an external memory device connected to CS[0] (normal boot mode).

EP7212 Interrupt Pin

Input State

Operating State Latency

Idle State Latency

Standby State Latency

nEXTFIQ

Not deglitched; must be Worst-case latency active for 20 µs to be of 20 µsec detected

Worst-case 20 µsec: if only single cycle instructions, less than 1 µsec

Including PLL / osc. settling time, approx. 0.25 sec when FASTWAKE = 0, or approx. 500 µsec when FASTWAKE = 1, or = Idle State if in 13 MHz mode with CLKENSL set

nEINT1–2

Not deglitched

Worst-case latency of 20 µsec

As above

EINT3

Not deglitched

Worst-case latency of 20 µsec

As above

nMEDCHG

Deglitched by 16 kHz Worst-case latency clock; must be active of 141 µsec for at least 125 µs to be detected

Worst-case 80 µsec: if only single cycle instructions, 125 µsec

As above (note difference if in 13 MHz mode with CLKENSL set)

Table 12. External Interrupt Source Latencies

If nMEDCHG is low, then the boot will be from the on-chip ROM. Note that in both cases, following the de-assertion of power on reset, the EP7212 will be in the Standby State and requires a low-to-high transition on the external WAKEUP pin in order to actually start the boot sequence. The effect of booting from the on-chip Boot ROM is to reverse the decoding for all chip selects internally. Table 13 shows this decoding. The control signal for the boot option is latched by nPOR, which means that the remapping of addresses and bus widths will continue to apply until nPOR is asserted again. After booting from the Boot ROM, the contents of the Boot ROM can be read back from address 0x00000000 onwards, and in normal state of operation the Boot ROM contents can be read back from address range 0x70000000.

3.8

Memory and I/O Expansion Interface

Six separate linear memory or expansion segments are decoded by the EP7212, two of which can be reserved for two PC Card cards, each interfacing to a separate single CL-PS6700 device. Each segment is 256 Mbytes in size. Two additional segments (i.e., in addition to these six) are dedicated to the on-chip SRAM and the on-chip ROM. The on-chip ROM space is fully decoded, and the SRAM space

Address Range

Chip Select

0000.0000–0FFF.FFFF

CS[7] (Internal only)

1000.0000–1FFF.FFFF

CS[6] (Internal only)

2000.0000–2FFF.FFFF

nCS[5]

3000.0000–3FFF.FFFF

nCS[4]

4000.0000–4FFF.FFFF

nCS[3]

5000.0000–5FFF.FFFF

nCS[2]

6000.0000–6FFF.FFFF

nCS[1]

7000.0000–7FFF.FFFF

nCS[0]

Table 13. Chip Select Address Ranges After Boot From On-Chip Boot ROM

is fully decoded up to the maximum size of the video frame buffer programmed in the LCDCON register (128 kbytes). Beyond this address range the SRAM space is not fully decoded (i.e., any accesses beyond 128 kbyte range get wrapped around to within 128 kbyte range). Any of the six segments are configured to interface to a conventional SRAM-like interface, and can be individually programmed to be 8-, 16-, or 32-bits wide, to support page mode access, and to execute from 1 to 8 wait states for non-sequential accesses and 0 to 3 for burst mode accesses. The zero wait state sequential access feature is designed to support burst mode

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EP7212 ROMs. For writable memory devices which use the nMWE pin, zero wait state sequential accesses are not permitted and one wait state is the minimum which should be programmed in the sequential field of the appropriate MEMCFG register. Bus cycles can also be extended using the EXPRDY input signal. Page mode access is accomplished by setting SQAEN = 1, which enables accesses of the form one random address followed by three sequential addresses, etc., while keeping nCS asserted. These sequential bursts can be up to four words long before nCS is released to allow DMA and refreshes to take place. This can significantly improve bus bandwidth to devices such as ROMs which support page mode. When SQAEN = 0, all accesses to memory are by random access without nCS being de-asserted between accesses. Again nCS is de-asserted after four consecutive accesses to allow DMAS. Bits 5 and 6 of the SYSCON2 register independently enable the interfaces to the CL-PS6700 (PC Card slot drivers). When either of these interfaces are enabled, the corresponding chip select (nCS4 and/or nCS5) becomes dedicated to that CL-PS6700 interface. The state of SYSCON2 bit 5 determines the function of chip select nCS4 (i.e., CL-PS6700 interface or standard chip select functionality); bit 6 controls nCS5 in a similar way. There is no interaction between these bits. For applications that require a display buffer smaller than 38,400 bytes, the on-chip SRAM can be used as the frame buffer. The width of the boot device can be chosen by selecting values of PE[1] and PE[0] during power on reset. The inputs in Table 14 are latched by the rising edge of nPOR to select the boot option.

3.9

DRAM Controller with EDO Support

The DRAM controller in the EP7212 provides all the connections to directly interface to up to two

DS474PP1

PE[1]

PE[0]

Boot Block (nCS0)

32-bit

8-bit

16-bit

Undefined

Table 14. Boot Options

banks of (EDO) DRAM, and the width of the memory interface is programmable to 16-bits or 32-bits. Both banks have to be of the same width. The 16/32-bit DRAM width selection is made based on bit 2 of the SYSCON2 register. Each of the two banks supported can be up to 256 Mbytes in size. Two RAS lines and four CAS lines are provided, with one CAS line per byte lane. The DRAM controller does not support device size programmability. Therefore, if two banks are implemented and DRAM devices are used, a bank smaller than 256 Mbytes would be created leading to a segmented memory map. Each segmented bank will be separated by 256 Mbytes. Segments that are smaller than the bank size will repeat within the bank. Table 15. Physical to DRAM Address Mapping shows the mapping of the physical address to DRAM row and column addresses. This mapping has been organized to support any DRAM device size from 4 Mbits to 1 Gbits with a square row and column configuration (i.e., the number of column addresses is equal to the number of row addresses). If a non-square DRAM is used, further fragmentation of the memory map will occur, however the smallest contiguous segment will always be 1 Mbyte. With proper mapping of pages/sections by the MMU, one can create contiguous memory blocks. On boot-up, the DRAM controller is configured for operation with an 18.432 MHz internal bus speed, and therefore, can support either fast page mode or EDO DRAM. In this case, the read data from the DRAM is latched within the EP7212 on the rising edge of the nCAS output strobes. The DRAM must 31

EP7212 not have an access time greater than 70 ns in order to meet the 18 MHz timing requirements. When the internal bus is operating at 36.864 MHz (i.e., for CPU clock frequencies of 36.864, 49.152, or 73.728 MHz), the DRAM controller will only operate with EDO DRAM. When operating at 36 MHz, the EDO DRAM must not have an access time greater than 50 ns. The DRAM cycle timings are adjusted to take advantage of the additional performance available from fast EDO DRAM. In EDO mode, the EP7212 design relies on the DRAM data being driven to be available on the external data bus during the entire high phase of the nCAS signal so that it can be latched towards the end of the cycle. In Fast Page mode, the data should be latched at the rising edge of nCAS. It is not possible to use

the EP7212 with fast page mode DRAM at operating frequencies of 36 MHz or higher. The DRAM controller breaks all sequential access, so that the minimum page sizes defined can be supported. All of the possible page sizes are multiples of the minimum page size, so by breaking up accesses on minimum page sizes by default, all accesses crossing larger page boundaries are broken up. Table 16 DRAM Address Mapping for a 32-Bit DRAM Memory System shows the address mapping for various DRAMâ&#x20AC;&#x2122;s with square and nonsquare row and address inputs. This assumes two x16 devices are connected to each RAS line with 32-bit wide DRAM operation selected. This mapping is then repeated every 256 Mbytes for each

DRAM Address Pins

DRAM Column x16 Mode

DRAM Column x32 Mode

DRAM Row x16 Mode

DRAM Row x32 Mode

7212 Pin Name

A11

A10

A[27]/DRA[0]

A10

A11

A[26]/DRA[1]

A11

A12

A[25]/DRA[2]

A12

A13

A[24]/DRA[3]

A13

A14

A[23]/DRA[4]

A14

A15

A[22]/DRA[5]

A15

A16

A[21]/DRA[6]

A16

A17

A[20]/DRA[7]

A18

A19

A17

A18

A[19]/DRA[8]

A20

A21

A19

A20

A[18]/DRA[9]

A22

A23

A21

A22

A[17]/DRA[10]

A24

A25

A23

A24

A[16]/DRA[11]

A26

A27

A25

A26

A[15]/DRA[12]

Table 15. Physical to DRAM Address Mapping 1. This bit will be generated by the DRAM controller.

An example of the DRAM connections for a typical system can be found in Figure 12. A Maximum EP7212 Based System on page 52.

DS474PP1

EP7212 DRAM bank. The placeholder ‘n’ below is equal to 0xC + bank number (i.e., 0xC for bank 0, 0xD for bank 1). The DRAM controller contains a programmable refresh counter. The refresh rate is controlled using the DRAM refresh period register (DRFPR). The 16/32-bit DRAM selection is made based on bit 2 of the SYSCON2 register. Both banks must have the same width. SYSCON2 0x8000 1100 Bit 2 (DRAMSZ)

0 = 32-bit DRAM 1 = 16-bit DRAM

The default is 32-bit width, since the SYSCON2 register is reset to all zeros on power-up.

3.10

CL-PS6700 PC Card Controller Interface

Two of the expansion memory areas are dedicated to supporting up to two CL-PS6700 PC Card controller devices. These are selected by nCS4 and nCS5 (must first be enabled by bits 5 and 6 of SYSCON2). For efficient, low power operation, both address and data are carried on the lower 16 bits of the EP7212 data bus. Accesses are initiated by a write or read from the area of memory allocated for nCS4 or nCS5. The memory map within each of these areas is segmented to allow different types of PC Card accesses to take place, for attribute, I/O, and common memory space. The CLPS6700 internal registers are memory mapped within the address space as shown in Table 17. NOTE:

Due to the operating speed of the CLPS6700, this interface is supported only for processor speeds of 13 and 18 MHz.

EP7212 Size

Address Configuration

Total Size of Bank

Address Range of Segment(s)

Size of Segment(s)

4 Mbit

9 Row x 9 Column

0.5 Mbyte

n000.0000–n007.FFFF

0.5 MByte

16 Mbit

10 Row x 10 Column

2 Mbytes

n000.0000–n01F.FFFF

2 Mbytes

16 Mbit

12 Row x 8 Column

2 Mbytes

n000.0000–n003.FFFF n008.0000–n00B.FFFF n020.0000–n023.FFFF n028.0000–n02B.FFFF n080.0000–n083.FFFF n088.0000–n08B.FFFF n0A0.0000–n0A3.FFFF n0A8.0000–n0AB.FFFF

256 KBytes 256 KBytes 256 KBytes 256 KBytes 256 KBytes 256 KBytes 256 KBytes 256 KBytes

64 Mbit

11 Row x 11 Column

8 Mbytes

n000.0000–n07F.FFFF

8 Mbytes

64 Mbit

13 Row x 9 Column

8 Mbytes

n000.0000–n00F.FFFF n020.0000–n02F.FFFF n080.0000–n08F.FFFF n0A0.0000–n0AF.FFFF n200.0000–n20F.FFFF n220.0000–n22F.FFFF n280.0000–n28F.FFFF n2A0.0000–n2AF.FFFF

1 MByte 1 MByte 1 MByte 1 MByte 1 MByte 1 MByte 1 MByte 1 MByte

256 Mbit

12 Row x 12 Column

32 Mbytes

n000.0000–n1FF.FFFF

32 Mbytes

1 Gbit

13 Row x 13 Column

128 Mbytes

n000.0000–n7FF.FFFF

128 Mbytes

Table 16. DRAM Address Mapping When Connected to an External 32-Bit DRAM Memory System

DS474PP1

EP7212 A complete description of the protocol and AC timing characteristics can be found in the CL-PS6700 data sheet. A transaction is initiated by an access to the nCS4 or nCS5 area. The chip select is asserted, and on the first clock, the upper 10 bits of the PC Card address, along with 6 bits of size, space, and slot information are put out onto the lower 16 bits of the EP7212’s data bus. Only word (i.e., 4-byte) and single-byte accesses are supported, and the slot field is hardcoded to 11, since the slot field is defined as a ‘Reserved field’ by the CL-PS6700. The chip selects are used to select the device to be accessed. The space field is made directly from the A26 and A27 CPU address bits, according to the decode shown in Table 18. The size field is forced to 11 if a word access is required, or to 00 if a byte access is required. This avoids the need to configure the interface after a reset. On the second clock cycle, the remaining 16 bits of the PC Card address are multiplexed out onto the lower 16 bits of the data bus. If the transaction selected is a CL-PS6700 register transaction, or a write to the PC Card (as-

Access Type

suming there is space available in the CL-PS6700’s internal write buffer) then the access will continue on the following two clock cycles. During these following two clock cycles the upper and lower halves of the word to be read or written will be put onto the lower 16 bits of the main data bus. The ‘ptype’ signal on the CL-PS6700s should be connected to the EP7212’s WRITE output pin. During PC Card accesses, the polarity of this pin changes, and it becomes low to signify a write and high to signify a read. It is valid with the first half word of the address. During the second half word of the address, it is always forced high to indicate to the CL-PS6700 that the EP7212 has initiated either the write or read. The PRDY signals from each of the two CLPS6700 devices are connected to Port B bits 0 and 1, respectively. When the PC CARD1 or PC CARD2 control bits in the SYSCON2 register are de-asserted, these port bits are available for GPIO. When asserted, these port bits are used as the

Addresses for CL-PS6700 Interface 1

Addresses for CL-PS6700 Interface 2

Attribute

0x40000000–0x43FFFFFF

0x50000000– 0x53FFFFFF

I/O

0x44000000–0x47FFFFFF

0x54000000–0x57FFFFFF

Common memory

0x48000000–0x4BFFFFFF

0x58000000–0x5BFFFFFF

CL-PS6700 registers

0x4C000000–0x4FFFFFFF

0x5C000000–0x5FFFFFFF

Table 17. CL-PS6700 Memory Map

Space Field Value

PC CARD Memory Space

Attribute

I/O

Common memory

CL-PS6700 registers Table 18. Space Field Decoding

DS474PP1

EP7212 PRDY signals. When the PRDY signal is de-asserted (i.e., low), it indicates that the CL-PS6700 is busy accessing its card. If a PC CARD access is attempted while the device is busy, the PRDY signal will cause the EP7212’s CPU to be stalled. The EP7212’s CPU will have to wait for the card to become available. DMA transfers to the LCD can still continue in the background during this period of time (as described below). The EP7212 can access the registers in the CL-PS6700, regardless of the state of the PRDY signal. If the EP7212 needs to access the PC CARD via the CL-PS6700, it waits until the PRDY signal is high before initiating a transfer request. Once a request is sent, the PRDY signal indicates if data is available. In the case of a PC Card write, writes can be posted to the CL-PS6700 device, with the same timing as CL-PS6700 internal register writes. Writes will normally be completed by the CL-PS6700 device independent of the EP7212 processor activity. If a posted write times out, or fails to complete for any other reason, then the CL-PS6700 will issue an interrupt (i.e., a WR_FAIL interrupt). In the case where the CL-PS6700 write buffer is already full, the PRDY signal will be de-asserted (i.e., driven low) and the transaction will be stalled pending an available slot in the buffer. In this case, the EP7212’s CPU will be stalled until the write can be posted successfully. While the PRDY signal is deasserted, the chip select to the CL-PS6700 will be de-asserted and the main bus will be released so that DMA transfers to the LCD controller can continue in the background. In the case of a PC Card read, the PRDY signal from the CL-PS6700 will be de-asserted until the read data is ready. At this point, it will be reasserted and the access will be completed in the same way as for a register access. In the case of a byte access, only one 16-bit data transfer will be required to complete the access. While the PRDY signal is deasserted, the chip select to the CL-PS6700 will be de-asserted, and the main bus will be released so DS474PP1

that DMA transfers to the LCD controller can continue in the background. The EP7212 will re-arbitrate for control of the bus when the PRDY signal is reasserted to indicate that the read or write transaction can be completed. The CPU will always be stalled until the PC Card access is completed. A card read operation may be split into a request cycle and a data cycle, or it may be combined into a single request/data transfer cycle. This depends on whether the data requested from the card is available in the prefetch buffer (internal to the CLPS6700). The request portion of the cycle, for a card read, is similar to the request phase for a card write (described above). If the requested data is available in the prefetch buffer, the CL-PS6700 asserts the PRDY signal before the rising edge of the third clock and the EP7212 continues the cycle to read the data. Otherwise, the PRDY signal is de-asserted, and the request cycle is stalled. The EP7212 may then allow the DMA address generator to gain control of the bus, to allow LCD refreshes to continue. When the CL-PS6700 is ready with the data, it asserts the PRDY signal. The EP7212 then arbitrates for the bus and, once the request is granted, the suspended read cycle is resumed. The EP7212 resumes the cycle by asserting the appropriate chip select, and data is transferred on the next two clocks if a word read (one clock if a byte read). There is no support within the EP7212 for detecting time-outs. The CL-PS6700 device must be programmed to force the cycle to be completed (with invalid data for a read) and then generate an interrupt if a read or write access has timed out (i.e., RD_FAIL or WR_FAIL interrupt). The system software can then determine which access was not successfully completed by reading the status registers within the CL-PS6700. The CL-PS6700 has support for DMA data transfers. However, DMA is supported only by software 35

EP7212 emulation because the DMA address generator built into the EP7212 is dedicated to the LCD controller interface. If DMA is enabled within the CLPS6700, it will assert its PDREQ signal to make a DMA request. This can be connected to one of the EP7212’s external interrupts and be used to interrupt the CPU so that the software can service the DMA request under program control. Each of the CL-PS6700 devices can generate an interrupt PIRQ. Since the PIRQ signal is an open drain on the CL-PS6700 devices, two CL-PS6700 devices may be wired OR’ed to the same interrupt. The circuit can then be connected to one of the EP7212’s active low external interrupt sources. On the receipt of an interrupt, the CPU can read the interrupt status registers on the CL-PS6700 devices to determine the cause of the interrupt. All transactions are synchronized to the EXPCLK output from the EP7212 in 18.432 MHz mode or the external 13 MHz clock. The EXPCLK should be permanently enabled, by setting the EXCKEN bit in the SYSCON1 register, when the CL-PS6700 is used. The reason for this is that the PC Card interface and CL-PS6700 internal write buffers need to be clocked after the EP7212 has completed its bus cycles. A GPIO signal from the EP7212 can be connected to the PSLEEP pin of the CL-PS6700 devices to allow them to be put into a power saving state before the EP7212 enters the Standby State. It is essential that the software monitor the appropriate status registers within the CL-PS6700s to ensure that there are no pending posted bus transactions before the Standby State is entered. Failure to do this will result in incomplete PC Card accesses.

3.11

Endianness

The EP7212 uses a little endian configuration for internal registers. However, it is possible to connect the device to a big endian external memory system. The big-endian / little-endian bit in the

ARM720T control register sets whether the EP7212 treats words in memory as being stored in big endian or little endian format. Memory is viewed as a linear collection of bytes numbered upwards from zero. Bytes 0 to 3 hold the first stored word, bytes 4 to 7 the second, and so on. In the little endian scheme, the lowest numbered byte in a word is considered to be the least significant byte of the word and the highest numbered byte is the most significant. Byte 0 of the memory system should be connected to data lines 7 through 0 (D[7:0]) in this scheme. In the big endian scheme the most significant byte of a word is stored at the lowest numbered byte, and the least significant byte is stored at the highest numbered byte. Therefore, byte 0 of the memory system should be connected to data lines 31 through 24 (D[31:24]). Load and store are the only instructions affected by the Endianness. Tables 19 and 20 demonstrate the behavior of the EP7212 in big and little endian mode, including the effect of performing non-aligned word accesses. The register definition section of this specification defines the behavior of the internal EP7212 registers in the big endian mode in more detail. For further information, refer to ARM Application Note 61, Big and Little Endian Byte Addressing.

3.12

Internal UARTs (Two) and SIR Encoder

The EP7212 contains two built-in UARTs that offers similar functionality to National Semiconductor’s 16C550A device. Both UARTs can support bit rates of up to 115.2 kbits/s and include two 16byte FIFOs: one for receive and one for transmit. One of the UARTs (UART1) supports the three modem control input signals CTS, DSR, and DCD. The additional RI input, and RTS and DTR output modem control lines are not explicitly supported but can be implemented using GPIO ports in the EP7212. UART2 has only the RX and TX pins.

DS474PP1

EP7212

Address (W/B)

Data in Memory (as seen by the EP7212)

Byte Lanes to Memory / Ports / Registers Big Endian Memory

Little Endian Memory

7:0

15:8

23:16

31:24

7:0

15:8

Word + 0 (W) 11223344

Word + 1 (W) 11223344

Word + 2 (W) 11223344

Word + 3 (W) 11223344

Word + 0 (H) 11223344

Word + 1 (H) 11223344

Word + 2 (H) 11223344

Word + 3 (H) 11223344

Word + 0 (B) 11223344

Word + 1 (B) 11223344 Word + 2 (B) 11223344 Word + 3 (B) 11223344 NOTE:

R0 Contents

23: 16 31: 24

Big Endian

Little Endian

11223344

44112233

33441122

22334411

00001122

00003344

22000011

44000033

00003344

00001122

44000033

22000011

00000011

00000044

00000022

00000033

00000022

00000044

00000011

dc = donâ&#x20AC;&#x2122;t care Table 19. Effect of Endianness on Read Operations

Address (W/B)

Byte Lanes to Memory / Ports / Registers Big Endian Memory

Little Endian Memory

7:0

15:8

23:16

31:24

7:0

15:8

23:16

31:24

Word + 0 (W)

11223344

Word + 1 (W)

11223344

Word + 2 (W)

11223344

Word + 3 (W)

11223344

Word + 0 (H)

11223344

Word + 1 (H)

11223344

Word + 2 (H)

11223344

Word + 3 (H)

11223344

Word + 0 (B)

11223344

Word + 1 (B)

11223344

Word + 2 (B)

11223344

Word + 3 (B)

11223344

NOTE:

Bold indicates active byte lane. Table 20. Effect of Endianness on Write Operations

DS474PP1

EP7212 UART operation and line speeds are controlled by the UBLCR1 (UART bit rate and line control). Three interrupts can be generated by UART1: RX, TX, and modem status interrupts. Only two can be generated by UART2: RX and TX. The RX interrupt is asserted when the RX FIFO becomes half full or if the FIFO is non-empty for longer than three character length times with no more characters being received. The TX interrupt is asserted if the TX FIFO buffer reaches half empty. The modem status interrupt for UART1 is generated if any of the modem status bits change state. Framing and parity errors are detected as each byte is received and pushed onto the RX FIFO. An overrun error generates an RX interrupt immediately. All error bits can be read from the 11-bit wide data register. The FIFOs can also be programmed to be one byte depth only (i.e., like a conventional 16450 UART with double buffering). The EP7212 also contains an IrDA (Infrared Data Association) SIR protocol encoder as a post-processing stage on the output of UART1. This encoder can be optionally switched into the TX and RX signals of UART1, so that these can be used to drive an infrared interface directly. If the SIR protocol encoder is enabled, the UART TXD1 line is held in the passive state and transitions of the RXD1 line will have no effect. The IrDA output pin is LEDDRV, and the input from the photodiode is PHDIN. Modem status lines will cause an interrupt (which can be masked) irrespective of whether the SIR interface is being used. Both the UARTs operate in a similar manner to the industry standard 16C550A. When CTS is deasserted on the UART, the UART does not stop shifting the data. It relies on software to take appropriate action in response to the interrupt generated.

Baud rates supported for both the UARTs are dependent on frequency of operation. When operating from the internal PLL, the interface supports various baud rates from 115.2 kbits/s downwards. The master clock frequency is chosen so that most of the required data rates are obtainable exactly. When operating with a 13.0 MHz external clock source, the baud rates generated will have a slight error, which is less than or equal to 0.75%. The rates (all measured in kbits/s) obtainable from the 13 MHz clock include: 9.6, 19.2, 38, 58, and 115.2. See UBRLCR1-2 UART1-2 Bit Rate and Line Control Registers for full details of the available bit rates in the 13 MHz mode.

3.13

Serial Interfaces

In addition to the two UARTs, the EP7212 offers the following serial interfaces shown in Table 21. The inputs / outputs of three of the serial interfaces (DAI, codec, and SSI2) are multiplexed onto a single set of external interface pins. If the DAISEL bit of SYSCON3 is low, then either SSI2 or the codec interface will be selected to connect to the external pins. When bit 0 of SYSCON2 (SERSEL) is high, then the codec is connected to the external pins, when low the master / slave SSI2 is connected to these pins. When the DAISEL bit is set high, the DAI interface is connected to the external pins. On power up, both the DAISEL and SERSEL bits are reset low, thus the master / slave SSI2 will be connected to these pins (and configured for slave mode operation to avoid external drive clashes). Table 22 contains pin definition information for the three multiplexed interfaces. The internal names given to each of the three interfaces are unique to help differentiate them from each other. The sections below that describe each of the three interfaces will use their respective unique internal pin names for clarity.

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EP7212 3.13.1

Codec Sound Interface

The codec interface allows direct connection of a telephony type codec to the EP7212. It provides all the necessary clocks and timing pulses. It also performs a parallel to serial conversion or vice versa on the data stream to or from the external codec device. The interface is full duplex and contains two separate data FIFOs (16 deep by 8-bits wide, one for the receive data, another for the transmit data). Data is transferred to or from the codec at 64 kbits/s. The data is either written to or read from the appropriate 16-byte FIFO. If enabled, a codec interrupt (CSINT) will be generated after every 8 bytes are transferred (FIFO half full/empty). This means the interrupt rate will be every 1 msec, with a latency of 1 msec.

Type

Comments

Transmit and receive modes are enabled by asserting high both the CDENRX and CDENTX codec enable bits in the SYSCON1 register. NOTE:

Both the CDENRX and CDENTX enable bits should be asserted in tandem for data to be transmitted or received. The reason for this is that the interrupt generation will occur 1 msec after one of the FIFOs is enabled. For example: If the receive FIFO gets enabled first and the transmit FIFO at a later time, the interrupt will occur 1 msec after the receive FIFO is enabled. After the first interrupt occurs, the receive FIFO will be half full. However, it will not be possible to know how full the transmit FIFO will be since it was enabled at a later time. Thus, it is possible to unintentionally overwrite data already in the transmit FIFO (See Figure 6).

After the CDENRX and CDENTX enable bits get asserted, the corresponding FIFOs become enabled. When both FIFOs are disabled, the FIFO staReferred To As

Max. Transfer Speed

SPI / Microwire 1

Master mode only

ADC Interface

128 kbits/s

SPI / Microwire 2

Master / slave mode

SSI2 Interface

512 kbits/s

DAI Interface

CD quality DACs and ADCs

DAI Interface

1.536 Mbits/s

Codec Interface

Only for use in the PLL clock mode

Codec Interface

64 kbits/s

Table 21. Serial Interface Options

Pin No. LQFP

External Pin Name

SSI2 Slave Mode (Internal Name)

SSI2 Master Mode

Codec Internal Name

DAI Internal Name

Strength

SSICLK

SSICLK = serial bit clock; Input

Output

PCMCLK = Output

SCLK = Output

SSITXFR

SSKTXFR = TX frame sync; Input

Output

PCMSYNC = Output

LRCK = Output

SSITXDA

SSITXDA = TX data; Output

Output

PCMOUT = Output

SDOUT = Output

SSIRXDA

SSIRXDA = RX data; Input

Input

PCMIN = Input

SDIN = Input

SSIRXFR

SSIRXFR = RX frame sync; Input

Output

p/u (use a 10k pull-up)

MCLK

Table 22. Serial-Pin Assignments

DS474PP1

EP7212 tus flag CRXFE is set and CTXFF is cleared so that the FIFOs appear empty. Additionally, if the CDENTX bit is low, the PCMOUT output is disabled. Asserting either of the two enable bits causes the sync and interrupt generation logic to become active; otherwise they are disabled to conserve power. Data is loaded into the transmit FIFO by writing to the CODR register. At the beginning of a transmit cycle, this data is loaded into a shift/load register. Just prior to the byte being transferred out, PCMSYNC goes high for one PCMCLK cycle. Then the data is shifted out serially to PCMOUT, MSB first, (with the MSB valid at the same time PCMSYNC is asserted). Data is shifted on the rising edge of the PCMCLK output. Receiving of data is performed by taking data in serially through PCMIN, again MSB first, shifting it through the shift/load register and loading the complete byte into the receive FIFO. If there is no data

available in the transmit FIFO, then a zero will be loaded into the shift/load register. Input data is sampled on the falling edge of PCMCLK. Data is read from the CODR register.

3.13.2

Digital Audio Interface

The DAI interface provides a high quality digital audio connection to DAI compatible audio devices. The DAI is a subset of I2S audio format that is supported by a number of manufacturers. The DAI interface produces one 128-bit frame at the audio sample frequency using a bit clock and frame sync signal. Digital audio data is transferred, full duplex, via separate transmit and receive data lines. The bit clock frequency is either fixed at 9.216 MHz or set via an externally supplied MCLK signal. The DAI interface contains separate transmit and receive FIFOâ&#x20AC;&#x2122;s. The transmit FIFOâ&#x20AC;&#x2122;s are 8 audio

CDENRX CDENTX CSINT

1 ms Interrupt occurs

Interrupt occurs

1 ms

Interrupt occurs

1 ms

Figure 6. Codec Interrupt Timing

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EP7212 samples deep and the receive FIFO’s are 12 audio samples deep.

3.13.2.1 DAI Operation Following reset, the DAI logic is disabled. To enable the DAI, the applications program should first clear the emergency underflow and overflow status bits, which are set following the reset, by writing a 1 to these register bits (in the DAISR register). Next, the DAI control register should be programmed with the desired mode of operation using a word write. The transmit FIFOs can either be “primed” by writing up to eight 16-bit values each, or can be filled by the normal interrupt service routine which handles the DAI FIFOs. Finally, the FIFOs for each channel must be enabled via writes

to DAIDR2. At this point, transmission/reception of data begins on the transmit (SDOUT) and receive (SDIN) pins. This is synchronously controlled by the 9.216 MHz (6.5 MHz in 13 MHz mode) internal clock or the externally supplied bit clock (SCLK), and the serial frame clock (LRCK).

3.13.2.2 DAI Frame Format Each DAI frame is 128 bits long and it comprises one audio sample. Of this 128-bit frame, only 32 bits are actually used for digital audio data. The remaining bits are output as zeros. The LRCK signal is used as a frame synchronization signal. Each transition of LRCK delineates the left and right halves of an audio sample. When LRCK transitions from high to low the next 16-bits make up the left

DAI ADC SCLK LRCK SDATA

7209 SDIN

MCLK

DAI DAC SCLK LRCK SDOUT MCLK

SCLK LRCK SDATA MCLK

CLOCK GEN

Figure 7. DAI Interface

DS474PP1

EP7212 SDIN

side of an audio sample. When LRCK transitions from low to high the next 16-bits make up the right side of an audio sample.

3.13.2.3 DAI Signals MCLK

SCLK

LRCK

SDOUT

oversampled clock. Used as an input to the EP7212 for generating the DAI timing. This signal is also usually used as an input to a DAC/ADC as an oversampled clock. This signal is fixed at 256 times the audio sample frequency. bit clock. Used as the bit clock input into the DAC/ADC. This signal is fixed at 128 times the audio sample frequency. Frame sync. Used as a frame synchronization input to the DAC/ADC. This signal is fixed at the audio sample frequency. This signal is clocked out on the negative going edge of SCLK. Digital audio data out. Used for sending playback data to a DAC. This signal is clocked out on the negative going edge of the SCLK output.

3.13.3

Digital audio input. Used for receiving record data from an ADC. This signal is latched by the EP7212 on the positive going edge of SCLK.

ADC Interface — Master Mode Only SSI1 (Synchronous Serial Interface)

The first synchronous serial interface allows interfacing to the following peripheral devices: •

In the default mode, the device is compatible with the MAXIM MAX148/9 in external clock mode. Similar SPI- or Microwire-compatible devices can be connected directly to the EP7212.

•

In the extended mode and with negative-edge triggering selected (the ADCCON and ADCCKNSEN bits are set, respectively, in the SYSCON3 register), this device can be interfaced to Analog Devices’ AD7811/12 chip using nADCCS as a common RFS/TFS line.

•

Other features of the devices, including power management, can be utilized by software and the use of the GPIO pins.

The clock output frequency is programmable and only active during data transmissions to save power. There are four output frequencies selectable, which will be slightly different depending whether

128 SCLKs Left Channel

LRCK

Right Channel

SCLK SDATA O

MSB

-1 -2 -3 -4 -5

+5 +4 +3 +2 +1

LSB

MSB

-1 -2 -3 -4

+5 +4 +3 +2 +1

SDATAI

MSB

-1 -2 -3 -4 -5

+5 +4 +3 +2 +1

LSB

MSB

-1 -2 -3 -4

+5 +4 +3 +2 +1

LSB

Figure 8. EP7212 Rev C - Digital Audio Interface Timing – MSB / Left Justified format

DS474PP1

EP7212 the device is operating in a 13 MHz mode or a 18.432 MHz–73.728 MHz mode (see Table 23). The required frequency is selected by programming the corresponding bits 16 and 17 in the SYSCON1 register. The sample clock (SMPCLK) always runs at twice the frequency of the shift clock (ADCCLK). The output channel is fed by an 8-bit shift register when the ADCCON bit of SYSCON3 is clear. When ADCCON is set, up to 16 bits of configuration command can be sent, as specified in the SYNCIO register. The input channel is captured by a 16-bit shift register. The clock and synchronization pulses are activated by a write to the output shift register. During transfers the SSIBUSY (synchronous serial interface busy) bit in the system status flags register is set. When the transfer is complete and valid data is in the 16-bit read shift register, the SSEOTI interrupt is asserted and the SSIBUSY bit is cleared. An additional sample clock (SMPCLK) can be enabled independently and is set at twice the transfer clock frequency. This interface has no local buffering capability and is only intended to be used with low bandwidth interfaces, such as for a touch-screen ADC interface.

3.13.4

Master / Slave SSI2 (Synchronous Serial Interface 2)

A second SPI / Microwire interface with full master / slave capability is provided by the EP7212. Data rates in slave mode are theoretically up to 512 kbits/s, full duplex, although continuous operation at this data rate will give an interrupt rate of 2 kHz, which is too fast for many operating systems. This would require a worst-case interrupt response time of less than 0.5 msec and would cause loss of data through TX underruns and RX overruns. The interface is fully capable of being clocked at 512 kHz when in slave mode. However, it is anticipated that external hardware will be used to frame the data into packets. Therefore, although the data would be transmitted at a rate of 512 kbits/s, the sustained data rate would in fact only be 85.3 kbits/s (i.e., 1 byte every 750 µsec). At this data rate, the required interrupt rate will be greater than 1 msec, which is acceptable. There are separate half-word-wide RX and TX FIFOs (16 half-words each) and corresponding interrupts which are generated when the FIFO’s are half-full or half-empty as appropriate. The inter-

SYSCON1 bit 17

SYSCON1 bit 16

13.0 MHz Operation ADCCLK Frequency (kHz)

18.432–73.728 MHz Operation ADCCLK Frequency (kHz)

4.2

16.9

67.7

135.4

128

Table 23. ADC Interface Operation Frequencies

DS474PP1

EP7212 rupts are called SS2RX and SS2TX, respectively. Register SS2DR is used to access the FIFOs.

bit sent (i.e., MSB). It is not possible to send data LSB first.

There are five pins to support this SSI port: SSIRXDA, SSITXFR, SSICLK, SSITXDA, and SSIRXFR. The SSICLK, SSIRXDA, SSIRXFR, and SSITXFR signals are inputs and the SSITXDA signal is an output in slave mode. In the master mode, SSICLK, SSITXDA, SSITXFR, and SSIRXFR are outputs, and SSIRXDA is an input. Master mode is enabled by writing a one to the SS2MAEN bit (SYSCON2[9]). When the master / slave SSI is not required, it can be disabled to save power by writing a zero to the SS2TXEN and the SS2RXEN bits (SYSCON2[4] [7]). When set, these two bits independently enable the transmit and receive sides of the interface.

When operating in master mode, the clock frequency is selected to be the same as the ADC interfaceâ&#x20AC;&#x2122;s (master mode only SSI1) â&#x20AC;&#x201D; that is, the frequencies are selected by the same bits 16 and 17 of the SYSCON1 register (i.e., the ADCKSEL bits). Thus, the maximum frequency in master mode is 128 kbits/s. The interface will support continuous transmission at this rate assuming that the OS can respond to the interrupts within 1 msec to prevent over/underruns.

The master / slave SSI is synchronous, full duplex, and capable of supporting serial data transfers between two nodes. Although the interface is byteoriented, data is loaded in blocks of two bytes at a time. Each data byte to be transferred is marked by a frame sync pulse, lasting one clock period, and located one clock prior to the first bit being transferred. Direction of the SSI2 ports, in slave and master mode, is shown in Figure 9. Data on the link is sent MSB first and coincides with an appropriate frame sync pulse, of one clock in duration, located one clock prior to the first data

Slave 7212

NOTE:

To allow synchronization to the incoming slave clock, the interface enable bits will not take effect until one SSICLK cycle after they are written and the value read back from SYSCON2. The enable bits reflect the real status of the enables internally. Hence, there will be a delay before the new value programmed to the enable bits can be read back.

The timing diagram for this interface can be found in the AC Characteristics section of this document.

3.13.4.1 Read Back of Residual Data All writes to the transmit FIFO must be in halfwords (i.e., in units of two bytes at a time). On the receive side, it is possible that an odd number of bytes will be received. Bytes are always loaded into the receive FIFO in pairs. Consequently, in the case of a single residual byte remaining at the end of a transmission, it will be necessary for the software Master 7212

SSIRXFR

SSITXFR

SSICLK

SSIRXDA

SSITXDA

SSIRXDA

Figure 9. SSI2 Port Directions in Slave and Master Mode

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EP7212 to read the byte separately. This is done by reading the status of two bits in the SYSFLG2 register to determine the validity of the residual data. These two bits (RESVAL, RESFRM) are both set high when a residual is valid. RESVAL is cleared on either a new transmission or on reading of the residual bit by software. RESFRM is cleared only on a new transmission. By popping the residual byte into the RX FIFO and then reading the status of these bits it is possible to determine if a residual bit has been correctly read. Figure 10 illustrates this procedure. The sequence is as follows: read the RESVAL bit, if this is a 0, no action needs to be taken. If this is a 1, then pop the residual byte into the FIFO by writing to the SS2POP location. Then read back the two status bits RESVAL and RESFRM. If these bits read back 01, then the residual byte popped into the FIFO is valid and can be read back from the SS2DR register. If the bits are not 01, then there has been another transmission received since the residual read procedure has been started. The data item that has been popped to the top of the FIFO will be invalid and should be ignored. In this case, the correct byte will have been stored in the most significant byte of the next half-word to be clocked into the FIFO. NOTE:

All the writes / reads to the FIFO are done word at a time (data on the lower 16 bits is valid and upper 16 bits are ignored).

Software manually pops the residual byte into the RX FIFO by writing to the SS2POP location (the value written is ignored). This write will strobe the RX FIFO write signal, causing the residual byte to be written into the FIFO. Figure 10. Residual Byte Reading

3.13.4.2 Support for Asymmetric Traffic The interface supports asymmetric traffic (i.e., unbalanced data flow). This is accomplished through separate transmit and receive frame sync control lines. In operation, the receiving node receives a byte of data on the eight clocks following the asser-

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Residual bit valid

11 New RX byte received

Pop FIFO New RX byte received

tion of the receive frame sync control line. In a similar fashion, the sending node can transmit a byte of data on the eight clocks following the assertion of the transmit frame sync pulse. There is no correlation in the frequency of assertions of the RX and TX frame sync control lines (SSITXFR and SSIRXFR). Hence, the RX path may bear a greater data throughput than the TX path, or vice versa. Both directions, however, have an absolute maximum data throughput rate determined by the maximum possible clock frequency, assuming that the interrupt response of the target OS is sufficiently quick.

3.13.4.3 Continuous Data Transfer Data bytes may be sent / received in a contiguous manner without interleaving clocks between bytes. The frame sync control line(s) are eight clocks apart and aligned with the clock representing bit D0 of the preceding byte (i.e., one bit in advance of the MSB).

3.13.4.4 Discontinuous Clock In order to save power during the idle times, the clock line is put into a static low state. The master is responsible for putting the link into the Idle State. The Idle State will begin one clock, or more, after the last byte transferred and will resume at least one clock prior to the first frame sync assertion. To disable the clock, the TX section is turned off. In Master mode, the EP7212 does not support the discontinuous clock.

EP7212 3.13.4.5 Error Conditions RX FIFO overflows are detected and conveyed via a status bit in the SYSFLG2 register. This register should be accessed at periodic intervals by the application software. The status register should be read each time the RX FIFO interrupts are generated. At this time the error condition (i.e., overrun flag) will indicate that an error has occurred but cannot convey which byte contains the error. Writing to the SRXEOF register location clears the overrun flag. TX FIFO underflow condition is detected and conveyed via a bit in the SYSFLG2 register, which is accessed by the application software. A TX underflow error is cleared by writing data to be transmitted to the TX FIFO.

3.13.4.6 Clock Polarity Clock polarity is fixed. TX data is presented on the bus on the rising edge of the clock. Data is latched into the receiving device on the falling edge of the clock. The TX pin is held in a tristate condition when not transmitting.

3.14

LCD Controller with Support for OnChip Frame Buffer

The LCD controller provides all the necessary control signals to interface directly to a single panel multiplexed LCD. The panel size is programmable and can be any width (line length) from 32 to 1024 pixels in 16-pixel increments. The total video frame buffer size is programmable up to 128 kbytes. This equates to a theoretical maximum panel size of 1024 x 256 pixels in 4 bits-per-pixel mode. The video frame buffer can be located in any portion of memory controlled by the chip selects. Its start address will be fixed at address 0x0000000 within each chip select. The start address of the LCD video frame buffer is defined in the FBADDR[3:0] register. These bits become the most significant nibble of the external address bus. The default start address is 0xC000 0000 (FBADDR = 0xC). A system built using the on-chip SRAM

(OCSR), will then serve as the LCD video frame buffer and miscellaneous data store. The LCD video frame buffer start address should be set to 0x6 in this option. Programming of the register FBADDR is only permitted when the LCD is disabled (this is to avoid possible cycle corruption when changing the register contents while a LCD DMA cycle is in progress). There is no hardware protection to prevent this. It is necessary for the software to disable the LCD controller before reprogramming the FBADDR register. Full address decoding is provided for the OCSR, up to the maximum video frame buffer size programmable into the LCDCON register. Beyond this, the address is wrapped around. The frame buffer start address must not be programmed to 0x4 or 0x5 if either CL-PS6700 interface is in use (PCMEN1 or PCMEN2 bits in the SYSCON2 register are enabled). FBADDR should never be programmed to 0x7 or 0x8, as these are the locations for the on-chip Boot ROM and internal registers. The screen is mapped to the video frame buffer as one contiguous block where each horizontal line of pixels is mapped to a set of consecutive bytes or words in the video RAM. The video frame buffer can be accessed word wide as pixel 0 is mapped to the LSB in the buffer such that the pixels are arranged in a little endian manner. The pixel bit rate, and hence the LCD refresh rate, can be programmed from 18.432 MHz to 576 kHz when operating in 18.432â&#x20AC;&#x201C;73.728 MHz mode, or 13 MHz to 203 kHz when operating from a 13 MHz clock. The LCD controller is programmed by writing to the LCD control register (LCDCON). The LCDCON register should not be reprogrammed while the LCD controller is enabled. The LCD controller also contains two 32-bit palette registers, which allow any 4-, 2-, or 1-bit pixel value to be mapped to any of the 15 grayscale values available. The required DMA bandwidth to support a Â˝ VGA panel displaying 4 bits-per-pixel data at

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EP7212 an 80 Hz refresh rate is approximately 6.2 Mbytes/sec. Assuming the frame buffer is stored in a 32-bit wide the maximum theoretical bandwidth available is 86 Mbytes/sec at 36.864 MHz, or 29.7 Mbytes/sec at 13 MHz. The LCD controller uses a nine stage 32-bit wide FIFO to buffer display data. The LCD controller requests new data when there are five words remaining in the FIFO. This means that for a ½ VGA display at 4 bits-per-pixel and 80 Hz refresh rate, the maximum allowable DMA latency is approximately 3.25 µsec ((5 words x 8 bits/byte) / (640 x 240 x 4bpp x 80 Hz)) = 3.25 µsec). The worst-case latency is the total number of cycles from when the DMA request appears to when the first DMA data word actually becomes available at the FIFO. DMA has the highest priority, so it will always happen next in the system. The maximum number of cycles required is 36 from the point at which the DMA request occurs to the point at which the STM is complete, then another 6 cycles before the data actually arrives at the FIFO from the first DMA read. This creates a total of 42 cycles. Assuming the frame buffer is located in 32-bit wide, the worst-case latency is almost exactly 3.2 µs, with 13 MHz page mode cycles. With each cycle consuming ~77 ns (i.e., 1/1 MHz), the value of 3.2 µs comes from 42 cycles x 77 ns/cycle = ~3.23 µsec. If 16-bit wide, then the worst-case latency will double. In this case, the maximum permissible display size will be halved, to approximately 320 x 240 pixels, assuming the same pixel depth and refresh rate has to be maintained. If the frame buffer is to be stored in static memory, then further calculations must be performed. If 18 MHz mode is selected, and 32-bit wide, then the worst-case latency will be 2.26 µsec (i.e., 42 cycles x 54 nsec/cycle). If 36 MHz mode is selected, and 32-bit wide, then the worst-case latency drops down to 1.49 µs. This calculation is a little more complex for 36 MHz mode of operation. The total number of cycles = (12 x 4) + 7 = 55. Thus, 55 x 27 ns = ~1.49 µsec.

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Figure 11 shows the organization of the video map for all combinations of bits-per-pixel. The refresh rate is not affected by the number of bits-per-pixel; however the LCD controller fetches twice the data per refresh for 4 bits-per-pixel compared to 2 bits-per-pixel. The main reason for reducing the number of bits-per-pixel is to reduce the power consumption of the memory where the video frame buffer is mapped.

3.15

Timer Counters

Two identical timer counters are integrated into the EP7212. These are referred to as TC1 and TC2. Each timer counter has an associated 16-bit read / write data register and some control bits in the system control register. Each counter is loaded with the value written to the data register immediately. This value will then be decremented on the second active clock edge to arrive after the write (i.e., after the first complete period of the clock). When the timer counter under flows (i.e., reaches 0), it will assert its appropriate interrupt. The timer counters can be read at any time. The clock source and mode are selectable by writing to various bits in the system control register. When run from the internal PLL, 512 kHz and 2 kHz rates are provided. When using the 13 MHz external source, the default frequencies will be 541 kHz and 2.115 kHz, respectively. However, only in non-PLL mode, an optional divide by 26 frequency can be generated (thus generating a 500 kHz frequency when using the 13 MHz source). This divider is enabled by setting the OSTB (Operating System Timing Bit) in the SYSCON2 register (bit 12). When this bit is set high to select the 500 kHz mode, the 500 kHz frequency is routed to the timers instead of the 541 kHz clock. This does not affect the frequencies derived for any of the other internal peripherals. The timer counters can operate in two modes: free running or pre-scale.

EP7212 3.15.1

Free Running Mode

3.15.2

In the free running mode, the counter will wrap around to 0xFFFF when it under flows and it will continue to count down. Any value written to TC1 or TC2 will be decremented on the second edge of the selected clock.

Prescale Mode

In the prescale mode, the value written to TC1 or TC2 is automatically re-loaded when the counter under flows. Any value written to TC1 or TC2 will be decremented on the second edge of the selected clock. This mode can be used to produce a programmable frequency to drive the buzzer (i.e., with TC1) or generate a periodic interrupt. The formula is F=(500 kHz) / (n+1).

Pixel 1 Pixel 2 Pixel 3 Pixel 4

Gray scale

Bit 0 Bit 1

Gray scale

Bit 2 Bit 3 Bit 4

Bit 5 Bit 6 Bit 7

4 Bits per pixel Pixel 1 Pixel 2 Pixel 3 Pixel 4

Gray scale Gray scale

Bit 0

Gray scale

Bit 1 Bit 2 Bit 3 Bit 4

Gray scale

Bit 5 Bit 6 Bit 7

2 Bits per pixel Pixel 1 Pixel 2 Pixel 3 Pixel 4

Gray scale

Gray scale Gray scale

Bit 0 Bit 1

Bit 2 Bit 3 Bit 4

Bit 5 Bit 6 Bit 7

1 Bit per pixel

Figure 11. Video Buffer Mapping

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EP7212 3.16

Real Time Clock

The EP7212 contains a 32-bit Real Time Clock (RTC). This can be written to and read from in the same way as the timer counters, but it is 32 bits wide. The RTC is always clocked at 1 Hz, generated from the 32.768 kHz oscillator. It also contains a 32-bit output match register, this can be programmed to generate an interrupt when the time in the RTC matches a specific time written to this register. The RTC can only be reset by an nPOR cold reset. Because the RTC data register is updated from the 1 Hz clock derived from the 32 kHz source, which is asynchronous to the main memory system clock, the data register should always be read twice to ensure a valid and stable reading. This also applies when reading back the RTCDIV field of the SYSCON1 register, which reflects the status of the six LSBs of the RTC counter.

3.16.1

Characteristics of the Real Time Clock Interface

When connecting a crystal to the RTC interface pins (i.e., RTCIN and RTCOUT), the crystal and circuit should conform to the following requirements: •

The 32.768 kHz frequency should be created by the crystals fundamental tone (i.e., it should be a fundamental mode crystal)

•

A start-up resistor is not necessary, since one is provided internally.

•

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•

The crystal should have a maximum 5 ppm frequency drift over the chip’s operating temperature range.

•

The voltage for the crystal must be 2.5 V + 0.2 V.

Alternatively, a digital clock source can be used to drive the RTCIN pin of the EP7212. With this approach, the voltage levels of the clock source should match that of the VDD supply for the EP7212’s pads (i.e., the supply voltage level used to drive all of the non-VDD core pins on the EP7212) (i.e., RTCOUT). The output clock pin should be left floating.

3.17

Dedicated LED Flasher

The LED flasher feature enables an external pin (PD[0] / LEDFLSH) to be toggled at a programmable rate and duty ratio, with the intention that the external pin is connected to an LED. This module is driven from the RTCs 32.768 kHz oscillator and works in all running modes because no CPU intervention is needed once its rate and duty ratio have been configured (via the LEDFLSH register). The LED flash rate period can be programmed for 1, 2, 3, or 4 seconds. The duty ratio can be programmed such that the mark portion can be 1/16, 2/16… 16/16 of the full cycle. The external pin can provide up to 4 mA of drive current.

3.18

Two PWM Interfaces

Two Pulse Width Modulator (PWM) duty ratio clock outputs are provided by the EP7212. When the device is operating from the internal PLL, the PWM will run at a frequency of 96 kHz. These signals are intended for use as drives for external DCto-DC converters in the Power Supply Unit (PSU) subsystem. External input pins that would normally be connected to the output from comparators monitoring the external DC-to-DC converter output are also used to enable these clocks. These are the FB[0:1] pins. The duty ratio (and hence PWMs on time) can be programmed from 1 in 16 to 15 in 16. The sense of the PWM drive signal (active high or

EP7212 low) is determined by latching the state of this drive signal during power on reset (i.e., a pull-up on the drive signal will result in a active low drive output, and visa versa). This allows either positive or negative voltages to be generated by the external DC-to-DC converter. PWMs are disabled by writing zeros into the drive ratio fields in the PMPCON Pump Control register. NOTE:

3.19

To maximize power savings, the drive ratio fields should be used to disable the PWMs, instead of the FB pins. The clocks that source the PWMs are disabled when the drive ratio fields are zeroed.

Boundary Scan

IEEE 1149.1 compliant JTAG is provided with the EP7212. Table 24 shows what instructions are supported in the EP7212. Instruction EXTEST

SCAN_N

Code 0000

0010

Description Places the selected scan chain in test mode. Connects the Scan Path Register between TDI and TDO

SAMPLE / PRELOAD

0011

NOTE: This instructio n i s i nc lu ded for product testing only and should never be used.

IDCODE

1110

Connects the ID register between TDI and TDO

BYPASS

1111

Connects a 1-bit shift register bit TDI and TDO

Table 24. Instructions Supported in JTAG Mode

The INTEST function will not be supported for the EP7212. Additional user-defined instructions exist, but these are not relevant to board-level testing. For

further information please refer to the ARM DDI 0087E ARM720T Data Sheet. As there are additional scan-chains within the ARM720T processor, it is necessary to include a scan-chain select function â&#x20AC;&#x201D; shown as SCAN_N in Table 24. To select a particular scan chain, this function must be input to the TAP controller, followed by the 4-bit scan chain identification code. The identification code for the boundary scan chain is 0011. Note that it is only necessary to issue the SCAN_N instruction if the device is already in the JTAG mode. The boundary scan chain is selected as the default on test-logic reset and any of the system resets. The contents of the device ID-register for the EP7212 are shown in Table 25. This is equivalent to 0x0F0F0F0F. Note this is the ID-code for the ARM720T processor.

3.20 3.20.1

In-Circuit Emulation Introduction

EmbeddedICEâ&#x201E;˘ is an extension to the architecture of the ARM family of processors, and provides the ability to debug cores that are deeply embedded into systems. It consists of three parts: 1) A set of extensions to the ARM core 2) The EmbeddedICE macrocell, which provides external access to the extensions 3) The EmbeddedICE interface, which provides communication between the host computer and the EmbeddedICE macrocell The EmbeddedICE macrocell is programmed, in a serial fashion, through the TAP controller on the ARM via the JTAG interface. The EmbeddedICE macrocell is by default disabled to minimize power usage, and must be enabled at boot-up to support this functionality.

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EP7212 3.20.2

NOTE:

Functionality

The ICEBreaker module consists of two real-time watchpoint units together with a control and status register. One or both of the units can be programmed to halt the execution of the instructions by the ARM processor. Execution is halted when either a match occurs between the values programmed into the ICEBreaker and the values currently appearing on the address bus, data bus, and the various control signals. Any bit can be masked to remove it from the comparison. Either unit can be programmed as a watchpoint (monitoring data accesses) or a breakpoint (monitoring instruction fetches).

A more detailed description is available in the ARM Software Development Toolkit User Guide and Reference Manual. The ICEBreaker module and its registers are fully described in the ARM7TDMI Data Sheet.

3.21

Maximum EP7212-Based System

A maximum configured system using the EP7212 is shown in Figure 12. This system assumes all of the DRAMs and ROMs are 16-bit wide devices. The keyboard may be connected to more GPIO bits than shown to allow greater than 64 keys, however these extra pins will not be wired into the WAKEUP pin functionality.

Using one of these watchpoint units, an unlimited number of software breakpoints (in RAM) can be supported by substitution of the actual code.

Version

The EXTERN[1:0] signals from the ICEBreaker module are not wired out in this device. This mechanism is used to allow watchpoints to be dependent on an external event. This behavior can be emulated in software via the ICEBreaker control registers.

Part number 0

Manufacturer ID 1

Table 25. Device ID Register

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EP7212

CRYSTAL

MOSCIN

DD[3:0]

CRYSTAL

RTCIN nCS[4] PB0 EXPCLK

CL1 CL2 FM M

LCD

COL[7:0]

CL-PS6700 PC CARD CONTROLLER

PC CARD SOCKET

KEYBOARD

D[31:0]

PA[7:0]

A[27:0]

PB[7:0]

nMOE WRITE

PD[7:0]

nRAS[1] nRAS[0]

×16 DRAM

nCAS[0] nCAS[1]

×16 DRAM

nCAS[2] nCAS[3]

EP7212

PE[2:0] nPOR nPWRFL BATOK nEXTPWR nBATCHG RUN WAKEUP DRIVE[1:0] FB[1:0] nCS[0] nCS[1]

×16 FLASH

DAISSICLK SSITXFR SSITXDA SSIRXDA

×16 FLASH

LEDDRV PHDIN CS[n] WORD

EXTERNAL MEMORYMAPPED EXPANSION

BUFFERS

NCS[2] NCS[3]

ADDITIONAL I/O

NOTE:

BUFFERS AND LATCHES

LEDFLSH

RXD1/2 TXD1/2 DSR CTS DCD ADCCLK nADCCS ADCOUT ADCIN SMPCLK

POWER SUPPLY UNIT AND COMPARATORS

DC INPUT

BATTERY

DC-TO-DC CONVERTERS

CODEC/SSI2/ DAI

IR LED AND PHOTODIODE

2× RS-232 TRANSCEIVERS

ADC

DIGITIZER

A system can only use one of the following peripheral interfaces at any given time: SSI2, codec, or DAI.

Figure 12. A Maximum EP7212 Based System

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EP7212 4. MEMORY MAP The lower 2 GByte of the address space is allocated to memory. The 0.5 GByte of address space from 0xC0000000 to 0xDFFFFFFF is allocated to DRAM. The 1.5 GByte, less 8 kbytes for internal registers, is not accessible in the EP7212. The MMU in the EP7212 should be programmed to generate an abort exception for access to this area. Internal peripherals are addressed through a set of internal memory locations from hex address 0x8000.0000 to 0x8000.3FFF. These are known as the internal registers in the EP7212. In Table 26, the memory map from 0x8000.000 to 0x8000.1FFF contains registers that are compatible with the CL-PS7111 (see Table 26). These were in-

cluded for backward compatibility and are referred to as old internal registers. Table 26 shows how the 4-Gbyte address range of the ARM720T processor (as configured within this chip) is mapped in the EP7212. The memory map shown assumes that two CL-PS6700 PC Card controllers are connected. If this functionality is not required, then the nCS[4] and nCS[5] memory is available. The external boot ROM is not fully decoded (i.e., the boot code will repeat within the 256-Mbyte space from 0x70000000 to 0x80000000). See Table 13 on page 30 for the memory map when booted from on chip boot ROM. The SRAM is fully decoded up to a maximum size of 128 kbytes. Access to any location above this range will be wrapped to within the range.

Address

Contents

Size

0xF000.0000

Reserved

256 Mbytes

0xE000.0000

Reserved

256 Mbytes

0xD000.0000

DRAM Bank 1

256 Mbytes

0xC000.0000

DRAM Bank 0

256 Mbytes

0x8000.4000

Unused

~1 Gbyte

0x8000.2000

Internal registers (new)

8 kbytes

0x8000.0000

Internal registers (old) (from 7111)

8 kbytes

0x7000.0000

Boot ROM (nCS[7])

128 bytes

0x6000.0000

SRAM (nCS[6])

38,400 bytes

0x5000.0000

PCMCIA-1 (nCS[5])

4 x 64 Mbytes

0x4000.0000

PCMCIA-0 (nCS[4])

4 x 64 Mbytes

0x3000.0000

Expansion (nCS[3])

256 Mbytes

0x2000.0000

Expansion (nCS[2])

256 Mbytes

0x1000.0000

ROM Bank 1 (nCS[1])

256 Mbytes

0x0000.0000

ROM Bank 0 (nCS[0])

256 Mbytes

Table 26. EP7212 Memory Map in External Boot Mode

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EP7212 5. REGISTER DESCRIPTIONS 5.1

Internal Registers

Table 27 shows the Internal Registers of the EP7212 that are compatible with the CL-PS7111 when the CPU is configured to a little endian memory system. Table 28 shows the differences that occur when the CPU is configured to a big endian memory system for byte-wide access to Ports A, B, and D. All the internal registers are inherently little endian (i.e., the least significant byte is attached to bits 7 to 0 of the data bus). Hence, the system Endianness affects the addresses required for byte accesses to the internal registers, resulting in a reversal of the byte address required to read / write a particular byte within a register. Note that the internal registers have been split into two groups – the “old” and the “new”. The old ones are the same as that used in CL-PS7111 and are there for compatibility. The new registers are for accessing the additional functionality of the DAI interface and the LED flasher. There is no effect on the register addresses for word accesses. Bits A[0:1] of the internal address bus are only decoded for Ports A, B, and D (to allow read / write to individual ports). For all other registers, bits A[0:1] are not decoded, so that byte reads will return the whole register contents onto the EP7212’s internal bus, from where the appropriate byte (according to the endianness) will be read by the CPU. To avoid the additional complexity, it is preferable to perform all internal register accesses as word operations, except for ports A to D which are explicitly designed to operate with byte accesses, as well as with word accesses. An 8 k segment of memory in the range 0x8000.0000 to 0x8000.3FFF is reserved for internal use in the EP7212. Accesses in this range will not cause any external bus activity unless debug mode is enabled. Writes to bits that are not explic-

itly defined in the internal area are legal and will have no effect. Reads from bits not explicitly defined in the internal area are legal but will read undefined values. All the internal addresses should only be accessed as 32-bit words and are always on a word boundary, except for the PIO port registers, which can be accessed as bytes. Address bits in the range A[0:5] are not decoded (except for Ports A–D), this means each internal register is valid for 64 bytes (i.e., the SYSFLG1 register appears at locations 0x8000.0140 to 0x8000.017C). There are some gaps in the register map for backward compatibility reasons, but registers located next to a gap are still only decoded for 64 bytes. The GPIO port registers are byte-wide and can be accessed as a word but not as a half-word. These registers additionally decode A[0:1]. All addresses are in hexadecimal notation. NOTE:

All byte-wide registers should be accessed as words (except Port A to Port D registers, which are designed to work in both word and byte modes). All registers bit alignment starts from the LSB of the register (i.e., they are all right shift justified). The registers which interact with the 32 kHz clock or which could change during readback (i.e., RTC data registers, SYSFLG1 register (lower 6-bits only), the TC1D and TC2D data registers, port registers, and interrupt status registers), should be read twice and compared to ensure that a stable value has been read back.

All internal registers in the EP7212 are reset (cleared to zero) by a system reset (i.e., nPOR, nRESET, or nPWRFL signals becoming active), and the Real Time Clock data register (RTCDR) and match register (RTCMR), which are only reset by nPOR becoming active. This ensures that the system time preserved through a user reset or power fail condition. In the following register descriptions, little endian is assumed.

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EP7212

Address

Name

Default RD/WR Size

Comments

0x8000.0000

PADR

Port A data register

0x8000.0001

PBDR

Port B data register

0x8000.0002

—

Reserved

0x8000.0003

PDDR

Port D data register

0x8000.0040

PADDR

Port A data direction register

0x8000.0041

PBDDR

Port B data direction register

0x8000.0042

—

Reserved

0x8000.0043

PDDDR

Port D data direction register

0x8000.0080

PEDR

Port E data register

0x8000.00C0

PEDDR

Port E data direction register

0x8000.0100

SYSCON1

System control register 1

0x8000.0140

SYSFLG1

System status flags register 1

0x8000.0180

MEMCFG1

Expansion memory configuration register 1

0x8000.01C0

MEMCFG2

Expansion memory configuration register 2

0x8000.0200

DRFPR

DRAM refresh period register

0x8000.0240

INTSR1

Interrupt status register 1

0x8000.0280

INTMR1

Interrupt mask register 1

0x8000.02C0

LCDCON

LCD control register

0x8000.0300

TC1D

Read / Write register sets and reads data to TC1

0x8000.0340

TC2D

Read / Write register sets and reads data to TC2

0x8000.0380

RTCDR

—

Real Time Clock data register

0x8000.03C0

RTCMR

—

Real Time Clock match register

0x8000.0400

PMPCON

PWM pump control register

0x8000.0440

CODR

CODEC data I/O register

0x8000.0480

UARTDR1

UART1 FIFO data register

0x8000.04C0

UBLCR1

UART1 bit rate and line control register

0x8000.0500

SYNCIO

Synchronous serial I/O data register for master only SSI

0x8000.0540

PALLSW

Least significant 32-bit word of LCD palette register

0x8000.0580

PALMSW

Most significant 32-bit word of LCD palette register

0x8000.05C0

STFCLR

—

Write to clear all start up reason flags

0x8000.0600

BLEOI

—

Write to clear battery low interrupt

0x8000.0640

MCEOI

—

Write to clear media changed interrupt

0x8000.0680

TEOI

—

Write to clear tick and watchdog interrupt

0x8000.06C0

TC1EOI

—

Write to clear TC1 interrupt

0x8000.0700

TC2EOI

—

Write to clear TC2 interrupt

Table 27. EP7212 Internal Registers (Little Endian Mode)

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EP7212 Address

Name

0x8000.0740

RTCEOI

—

Write to clear RTC match interrupt

0x8000.0780

UMSEOI

—

Write to clear UART modem status changed interrupt

0x8000.07C0

COEOI

—

Write to clear CODEC sound interrupt

0x8000.0800

HALT

—

Write to enter the Idle State

0x8000.0840

STDBY

—

Write to enter the Standby State

0x8000.0880– 0x8000.0FFF

Reserved

0x8000.1000

FBADDR

0xC

LCD frame buffer start address

0x8000.1100

SYSCON2

System control register 2

0x8000.1140

SYSFLG2

System status register 2

0x8000.1240

INTSR2

Interrupt status register 2

0x8000.1280

INTMR2

Interrupt mask register 2

0x8000.12C0– 0x8000.147F

Reserved

0x8000.1480

UARTDR2

UART2 Data Register

0x8000.14C0

UBLCR2

UART2 bit rate and line control register

0x8000.1500

SS2DR

Master / slave SSI2 data Register

0x8000.1600

SRXEOF

—

Write to clear RX FIFO overflow flag

0x8000.16C0

SS2POP

—

Write to pop SSI2 residual byte into RX FIFO

0x8000.1700

KBDEOI

—

Write to clear keyboard interrupt

0x8000.1800

Reserved

—

Do not write to this location. A write will cause the processor to go into an unsupported power savings state.

0x8000.1840– 0x8000.1FFF

Reserved

—

0x8000.2000

DAIR *

DAI control register

0x8000.2040

DAIR0 *

DAI data register 0

0x8000.2080

DAIDR1 *

DAI data register 1

0x8000.20C0

DAIDR2 *

DAI data register 2

0x8000.2100

DAISR *

DAI status register

0x8000.2200

SYSCON *

System control register 3

0x8000.2240

INTSR3 *

Interrupt status register 3

0x8000.2280

INTMR3 *

Interrupt mask register 3

LED Flash register

0x8000.22C0 LEDFLSH *

Default RD/WR Size

Comments

Write will have no effect, read is undefined

Table 27. EP7212 Internal Registers (Little Endian Mode) (cont.) * Internal registers that are not backward compatible with the CL-PS7111.

DS474PP1

EP7212

Big Endian Mode

Name

Default

RD/WR

Size

Comments

0x8000.0003

PADR

Port A Data Register

0x8000.0002

PBDR

Port B Data Register

0x8000.0001

—

Reserved

0x8000.0000

PDDR

Port D Data Register

0x8000.0043

PADDR

Port A data Direction Register

0x8000.0042

PBDDR

Port B Data Direction Register

0x8000.0041

—

Reserved

0x8000.0040

PDDDR

Port D Data Direction Register

0x0000.0080

PEDR

Port E Data Register

0X8000.0000

PEDDR

Port E Data Direction Register

Table 28. EP7212 Internal Registers (Big Endian Mode)

All internal registers in the IP7212 are reset (cleared to zero) by a system reset (i.e., nPOR, nURESET, or nPWRFL signals becoming active), except for the DRAM refresh period register (DPFPR), the Real Time Clock data register (RTCDR), and the match register (RTCMR), which are only reset by nPOR becoming active. This ensures that the DRAM contents and system time are preserved through a user reset or power fail condition. NOTE:

5.1.1

The following Register Descriptions refer to Little Endian Mode Only

PADR Port A Data Register

ADDRESS: 0x8000.0000 Values written to this 8-bit read / write register will be output on Port A pins if the corresponding data direction bits are set high (port output). Values read from this register reflect the external state of Port A, not necessarily the value written to it. All bits are cleared by a system reset.

5.1.2

PBDR Port B Data Register

ADDRESS: 0x8000.0001 Values written to this 8-bit read / write register will be output on Port B pins if the corresponding data direction bits are set high (port output). Values read from this register reflect the external state of Port B, not necessarily the value written to it. All bits are cleared by a system reset.

5.1.3

PDDR Port D Data Register

ADDRESS: 0x8000.0003 Values written to this 8-bit read / write register will be output on Port D pins if the corresponding data direction bits are set low (port output). Values read from this register reflect the external state of Port D, not necessarily the value written to it. All bits are cleared by a system reset.

DS474PP1

EP7212 5.1.4

PADDR Port A Data Direction Register

ADDRESS: 0x8000.0040 Bits set in this 8-bit read / write register will select the corresponding pin in Port A to become an output, clearing a bit sets the pin to input. All bits are cleared by a system reset.

5.1.5

PBDDR Port B Data Direction Register

ADDRESS: 0x8000.0041 Bits set in this 8-bit read / write register will select the corresponding pin in Port B to become an output, clearing a bit sets the pin to input. All bits are cleared by a system reset.

5.1.6

PDDDR Port D Data Direction Register

ADDRESS: 0x8000.0043 Bits cleared in this 8-bit read / write register will select the corresponding pin in Port D to become an output, setting a bit sets the pin to input. All bits are cleared by a system reset so that Port D is output by default.

5.1.7

PEDR Port E Data Register

ADDRESS: 0x8000.0080 Values written to this 3-bit read / write register will be output on Port E pins if the corresponding data direction bits are set high (port output). Values read from this register reflect the external state of Port E, not necessarily the value written to it. All bits are cleared by a system reset.

5.1.8

PEDDR Port E Data Direction Register

ADDRESS: 0x8000.00C0 Bits set in this 3-bit read / write register will select the corresponding pin in Port E to become an output, while the clearing bit sets the pin to input. All bits are cleared by a system reset so that Port E is input by default.

5.2

SYSTEM Control Registers

5.2.1

SYSCON1 The System Control Register 1

ADDRESS: 0x8000.0100 23

17:16

IRTXM

WAKEDIS

EXCKEN

ADCKSEL

SIREN

CDENRX

CDENTX

LCDEN

DBGEN

3:0

TC2S

TC2M

TC1S

TC1M

Keyboard scan

The system control register is a 21-bit read / write register which controls all the general configuration of the EP7212, as well as modes etc. for peripheral devices. All bits in this register are cleared by a system reset. The bits in the system control register SYSCON1 are defined in Table 29.

DS474PP1

EP7212 Bit 0:3

Description Keyboard scan: This 4-bit field defines the state of the keyboard column drives. The following table defines these states. Keyboard Scan

Column

All driven high

All driven low

2â&#x20AC;&#x201C;7

All high impedance (tristate)

Column 0 only driven high all others high impedance

Column 1 only driven high all others high impedance

Column 2 only driven high all others high impedance

Column 3 only driven high all others high impedance

Column 4 only driven high all others high impedance

Column 5 only driven high all others high impedance

Column 6 only driven high all others high impedance

Column 7 only driven high all others high impedance

TC1M: Timer counter 1 mode. Setting this bit sets TC1 to prescale mode, clearing it sets free running mode.

TC1S: Timer counter 1 clock source. Setting this bit sets the TC1 clock source to 512 kHz, clearing it sets the clock source to 2 kHz.

TC2M: Timer counter 2 mode. Setting this bit sets TC2 to prescale mode, clearing it sets free running mode.

TC2S: Timer counter 2 clock source. Setting this bit sets the TC2 clock source to 512 kHz, clearing it sets the clock source to 2 kHz.

UART1EN: Internal UART enable bit. Setting this bit enables the internal UART.

BZTOG: Bit to drive (i.e., toggle) the buzzer output directly when software mode of operation is selected (i.e., bit BZMOD = 0). See the BZMOD and BUZFREQ (SYSCON1) bits for more details.

BZMOD: This bit selects the buzzer drive mode. When BZMOD = 0, the buzzer drive output pin is connected directly to the BZTOG bit. This is the software mode. When BZMOD = 1, the buzzer drive is in the hardware mode. Two hardware sources are available to drive the pin. They are the TC1 or a fixed internally generated clock source. The selection of which source is used to drive the pin is determined by the state of the BUZFREQ bit in the SYSCON2 register. If the TC1 is selected, then the buzzer output pin is connected to the TC1 under flow bit. The buzzer output pin changes every time the timer wraps around. The frequency depends on what was programmed into the timer. See the description of the BUZFREQ and BZTOG bits (SYSCON2) for more details. Table 29. SYSCON1

DS474PP1

EP7212 Bit

Description

DBGEN: Setting this bit will enable the debug mode. In this mode, all internal accesses are output as if they were reads or writes to the expansion memory addressed by nCS5. nCS5 will still be active in its standard address range. In addition, the internal interrupt request and fast interrupt request signals to the ARM720T processor are output on Port E, bits 1 and 2. Note that these bits must be programmed to be outputs before this functionality can be observed. The clock to the CPU is output on Port E, Bit 0 to delineate individual accesses. For example, in debug mode: nCS5 = nCS5 or internal I/O strobe PE0 = CLK PE1 = nIRQ PE2 = nFIQ

LCDEN: LCD enable bit. Setting this bit enables the LCD controller.

CDENTX: Codec interface enable TX bit. Setting this bit enables the codec interface for data transmission to an external codec device.

CDENRX: Codec interface enable RX bit. Setting this bit enables the codec interface for data reception from an external codec device. NOTE: Both CDENRX and CDENTX need to be enabled / disabled in tandem, otherwise data may be lost.

SIREN: HP SIR protocol encoding enable bit. This bit will have no effect if the UART is not enabled.

16:17

ADCKSEL: Microwire / SPI peripheral clock speed select. This two-bit field selects the frequency of the ADC sample clock, which is twice the frequency of the synchronous serial ADC interface clock. The table below shows the available frequencies for operation when in PLL mode. These bits are also used to select the shift clock frequency for the SSI2 interface when set into master mode. The frequencies obtained in 13.0 MHz mode can be found in Table 23. ADCKSEL

ADC Sample Frequency (kHz) — SMPCLK

ADC Clock Frequency (kHz) — ADCCLK

128

256

128

EXCKEN: External expansion clock enable. If this bit is set, the EXPCLK is enabled continuously as a free running clock with the same frequency and phase as the CPU clock, assuming that the main oscillator is running. This bit should not be left set all the time for power consumption reasons. If the system enters the Standby State, the EXPCLK will become undefined. If this bit is clear, EXPCLK will be active during memory cycles to expansion slots that have external wait state generation enabled only.

WAKEDIS: Setting this bit disables waking up from the Standby State, via the wakeup input.

IRTXM: IrDA TX mode bit. This bit controls the IrDA encoding strategy. Clearing this bit means that each zero bit transmitted is represented as a pulse of width 3/16th of the bit rate period. Setting this bit means each zero bit is represented as a pulse of width 3/16th of the period of 115,200-bit rate clock (i.e., 1.6 µsec regardless of the selected bit rate). Setting this bit will use less power, but will probably reduce transmission distances. Table 29. SYSCON1 (cont.)

DS474PP1

EP7212 5.2.2

SYSCON2 System Control Register 2

ADDRESS: 0x8000.1100 15

11:10

Reserved

BUZFREQ

CLKENSL

OSTB

Reserved

SS2MAEN

UART2EN

SS2RXEN

PC CARD2

PC CARD1

SS2TXEN

KBWEN

DRAMSZ

KBD6

SERSEL

This register is an extension of SYSCON1, containing additional control for the EP7212, for compatibility with CL-PS7111. The bits of this second system control register are defined below. The SYSCON2 register is reset to all 0s on power up. Bit 0

Description SERSEL:The only affect of this bit is to select either SSI2 or the codec to interface to the external pins. See the table below for the selection options. NOTE: If the DAISEL bit of SYSCON3 is set, then it overrides the state of the SERSEL bit, and thus the external pins are connected to the DAI interface. SERSEL Value

Selected Serial Device to External Pins

Master / slave SSI2

Codec

KBD6: The state of this bit determines how many of the Port A inputs are ORâ&#x20AC;&#x2122;ed together to create the keyboard interrupt. When zero (the reset state), all eight of the Port A inputs will generate a keyboard interrupt. When set high, only Port A bits 0 to 5 will generate an interrupt from the keyboard. It is assumed that the keyboard row lines are connected into Port A.

DRAMZ: This bit determines the width of the DRAM memory interface, where: 0=32-bit DRAM and 1=16-bit DRAM.

KBWEN: When the KBWEN bit is high, the EP7212 will awaken from a power saving state into the Operating State when a high signal is on one of Port Aâ&#x20AC;&#x2122;s inputs (irrespective of the state of the interrupt mask register). This is called the Keyboard Direct Wakeup mode. In this mode, the interrupt request does not have to get serviced. If the interrupt is masked (i.e., the interrupt mask register 2 (INTMR2) bit 0 is low), the processor simply starts re-executing code from where it left off before it entered the power saving state. If the interrupt is non-masked, then the processor will service the interrupt.

SS2TXEN: Transmit enable for the synchronous serial interface 2. The transmit side of SSI2 will be disabled until this bit is set. When set low, this bit also disables the SSICLK pin (to save power) in master mode, if the receive side is low.

PC CARD1: Enable for the interface to the CL-PS6700 device for PC Card slot 1. The main effect of this bit is to reassign the functionality of Port B, bit 0 to the PRDY input from the CL-PS6700 devices, and to ensure that any access to the nCS4 address space will be according to the CL-PS6700 interface protocol. Table 30. SYSCON2

DS474PP1

EP7212 Bit

Description

PC CARD2: Enable for the interface to the CL-PS6700 device for PC Card slot 2. The main effect of this bit is to reassign the functionality of Port B, bit 1 to the PRDY input from the CL-PS6700 devices and to ensure that any access to the nCS5 address space will be according to the CL-PS6700 interface protocol.

SS2RXEN: Receive enable for the synchronous serial interface 2. The receive side of SSI2 will be disabled until this bit is set. When both SSI2TXEN and SSI2RXEN are disabled, the SSI2 interface will be in a power saving state.

UART2EN: Internal UART2 enable bit. Setting this bit enables the internal UART2.

SS2MAEN: Master mode enable for the synchronous serial interface 2. When low, SSI2 will be configured for slave mode operation. When high, SSI2 will be configured for master mode operation. This bit also controls the directionality of the interface pins.

OSTB: This bit (operating system timing bit) is for use only with the 13 MHz clock source mode. Normally it will be set low, however when set high it will cause a 500 kHz clock to be generated for the timers instead of the 541 kHz which would normally be available. The divider to generate this frequency is not clocked when this bit is set low.

CLKENSL: CLKEN select. When low, the CLKEN signal will be output on the RUN/CLKEN pin. When high, the RUN signal will be output on RUN/CLKEN.

BUZFREQ: The BUZFREQ bit is used to select which hardware source will be used as the source to drive the buzzer output pin. When BUZFREQ = 0, the buzzer signal generated from the on-chip timer (TC1) is output. When BUZFREQ = 1, a fixed frequency clock is output (500 Hz when running from the PLL, 528 Hz in the 13 MHz external clock mode). See the BZMOD and the BZTOG bits (SYSCON2) for more details. Table 30. SYSCON2 (cont.)

DS474PP1

EP7212 5.2.3

SYSCON3 System Control Register 3

ADDRESS: 0x8000.2200 15

Reserved

DAIEN

FASTWAKE

VERSN[2] Reserved

VERSN[1] Reserved

VERSN[0] Reserved

ADCCKNSEN

DAISEL

CLKCTL1

CLKCTL0

ADCCON

This register is an extension of SYSCON1 and SYSCON2, containing additional control for the EP7212. The bits of this third system control register are defined in Table 31. Bit

Description

ADCCON: Determines whether the ADC Configuration Extension field SYNCIO(31:16) is to be used for ADC configuration data. When this bit = 0 (default state) the ADC Configuration Byte SYNCIO(7:0) only is used for compatibility with the CL-PS7111. When this bit = 1, the ADC Configuration Extension field in the SYNCIO register is used for ADC Configuration data and the value in the ADC Configuration Byte (SYNCIO(6:0)) selects the length of the data (8-bit to 16-bit).

1:2

CLKCTL(1:0): Determines the frequency of operation of the processor and Wait State scaling. The table below lists the available options.

NOTE:

CLKCTL(1:0) Value

Processor Frequency

Memory Bus Frequency

Wait State Scaling

18.432 MHz

36.864 MHz

49.152 MHz

36.864 MHz

73.728 MHz

36.864 MHz

To determine the number of wait states programmed refer to Table 38 and Table 39. When operating at 13 MHz, the CLKCTL[1:0] bits should not be changed from the default value of ‘00’. Under no circumstances should the CLKCTL bits be changed using a buffered write.

DAISEL: When set selects the DAI Interface. This defaults to either the SSI (i.e., DAISEL bit is low).

ADCCKNSEN: When set, configuration data is transmitted on ADCOUT at the rising edge of the ADCCLK, and data is read back on the falling edge on the ADCIN pin. When clear (default), the opposite edges are used.

5:7

VERSN[0:2]: Additional read-only version bits — will read ‘001’ for Revision C and ‘010’ for Revision D EP7212 chips.

FASTWAKE: When set, the device will wake from the Standby State within one to two cycles of a 4 kHz clock. This bit is cleared at power up, and thus the device first starts using the default one to two cycles of the 8 Hz clock.

DAIEN: This bit enables the Digital Audio Interface when set (i.e., when DAIEN is high). Table 31. SYSCON3

DS474PP1

EP7212 5.2.4

SYSFLG1 â&#x20AC;&#x201D; The System Status Flags Register

ADDRESS: 0x8000.0140 31:30

VERID

BOOTBIT1

BOOTBIT0

SSIBUSY

21:16

UTXFF1

URXFE1

RTCDIV

UTXFF1

URXFE1

CLDFLG

PFFLG

RSTFLG

NBFLG

UBUSY1

7:4

DID

WUON

WUDR

DCDET

MCDR

The system status flags register is a 32-bit read only register, which indicates various system information. The bits in the system status flags register SYSFLG1 are defined in Table 32. Bit

Description

MCDR: Media changed direct read. This bit reflects the INVERTED non-latched status of the media changed input.

DCDET: This bit will be set if a non-battery operated power supply is powering the system (it is the inverted state of the nEXTPWR input pin).

WUDR: Wake up direct read. This bit reflects the non-latched state of the wakeup signal.

WUON: This bit will be set if the system has been brought out of the Standby State by a rising edge on the wakeup signal. It is cleared by a system reset or by writing to the HALT or STDBY locations.

4:7

DID: Display ID nibble. This 4-bit nibble reflects the latched state of the four LCD data lines. The state of the four LCD data lines is latched by the LCDEN bit, and so it will always reflect the last state of these lines before the LCD controller was enabled.

CTS: This bit reflects the current status of the clear to send (CTS) modem control input to UART1.

DSR: This bit reflects the current status of the data set ready (DSR) modem control input to UART1.

DCD: This bit reflects the current status of the data carrier detect (DCD) modem control input to UART1.

UBUSY1: UART1 transmitter busy. This bit is set while UART1 is busy transmitting data, it is guaranteed to remain set until the complete byte has been sent, including all stop bits.

NBFLG: New battery flag. This bit will be set if a low to high transition has occurred on the nBATCHG input, it is cleared by writing to the STFCLR location.

RSTFLG: Reset flag. This bit will be set if the RESET button has been pressed, forcing the nURESET input low. It is cleared by writing to the STFCLR location.

PFFLG: Power Fail Flag. This bit will be set if the system has been reset by the nPWRFL input pin, it is cleared by writing to the STFCLR location.

CLDFLG: Cold start flag. This bit will be set if the EP7212 has been reset with a power on reset, it is cleared by writing to the STFCLR location. Table 32. SYSFLG

DS474PP1

EP7212 Bit

Description

16:21

RTCDIV: This 6-bit field reflects the number of 64 Hz ticks that have passed since the last increment of the RTC. It is the output of the divide by 64 chain that divides the 64 Hz tick clock down to 1 Hz for the RTC. The MSB is the 32 Hz output, the LSB is the 1 Hz output.

URXFE1: UART1 receiver FIFO empty. The meaning of this bit depends on the state of the UFIFOEN bit in the UART1 bit rate and line control register. If the FIFO is disabled, this bit will be set when the RX holding register is empty. If the FIFO is enabled, the URXFE bit will be set when the RX FIFO is empty.

UTXFF1: UART1 transmit FIFO full. The meaning of this bit depends on the state of the UFIFOEN bit in the UART1 bit rate and line control register. If the FIFO is disabled, this bit will be set when the TX holding register is full. If the FIFO is enabled, the UTXFF bit will be set when the TX FIFO is full.

CRXFE: Codec RX FIFO empty bit. This will be set if the 16-byte codec RX FIFO is empty.

CTXFF: Codec TX FIFO full bit. This will be set if the 16-byte codec TX FIFO is full.

SSIBUSY: Synchronous serial interface busy bit. This bit will be set while data is being shifted in or out of the synchronous serial interface, when clear data is valid to read.

27:28

BOOTBIT0–1: These bits indicate the default (power-on reset) bus width of the ROM interface. See Memory Configuration Registers for more details on the ROM interface bus width. The state of these bits reflect the state of Port E[0:1] during power on reset, as shown in the table below. PE[1] (BOOTBIT1)

PE[0] (BOOTBIT0)

Boot option

32-bit

8-bit

16-bit

Reserved

ID: Will always read ‘1’ for the EP7212 device.

30:31

VERID: Version ID bits. These 2 bits determine the version id for the EP7212. Will read ‘10’ for the initial version. Table 32. SYSFLG (cont.)

DS474PP1

EP7212 5.2.5

SYSFLG2 System Status Register 2

ADDRESS: 0x8000.1140 23

21:12

10:7

UTXFF2

URXFE2

Reserved

UBUSY2

Reserved

CKMODE

SS2TXUF

SS2TXFF

SS2RXFE

RESFRM

RESVAL

SS2RXOF

This register is an extension of SYSFLG1, containing status bits for backward compatibility with CLPS7111. The bits of the second system status register are defined in Table 33. Bit

Description

SS2RXOF: Master / slave SSI2 RX FIFO overflow. This bit is set when a write is attempted to a full RX FIFO (i.e., when RX is still receiving data and the FIFO is full). This can be cleared in one of two ways: 1. Empty the FIFO (remove data from FIFO) and then write to SRXEOF location. 2. Disable the RX (affects of disabling the RX will not take place until a full SSI2 clock cycle after it is disabled)

RESVAL: Master / slave SSI2 RX FIFO residual byte present, cleared by popping the residual byte into the SSI2 RX FIFO or by a new RX frame sync pulse.

RESFRM: Master / slave SSI2 RX FIFO residual byte present, cleared only by a new RX frame sync pulse.

SS2RXFE: Master / slave SSI2 RX FIFO empty bit. This will be set if the 16 x 16 RX FIFO is empty.

SS2TXFF: Master / slave SSI2 TX FIFO full bit. This will be set if the 16 x 16 TX FIFO is full. This will get cleared when data is removed from the FIFO or the EP7212 is reset.

SS2TXUF: Master / slave SSI2 TX FIFO Underflow bit. This will be set if there is attempt to transmit when TX FIFO is empty. This will be cleared when FIFO gets loaded with data.

CKMODE: This bit reflects the status of the CLKSEL (PE[2]) input, latched during nPOR. When low, the PLL is running and the chip is operating in 18.432â&#x20AC;&#x201C;73.728 MHz mode. When high the chip is operating from an external 13 MHz clock.

UBUSY2: UART2 transmitter busy. This bit is set while UART2 is busy transmitting data; it is guaranteed to remain set until the complete byte has been sent, including all stop bits.

URXFE2: UART2 receiver FIFO empty. The meaning of this bit depends on the state of the UFIFOEN bit in the UART2 bit rate and line control register. If the FIFO is disabled, this bit will be set when the RX holding register contains is empty. If the FIFO is enabled, the URXFE bit will be set when the RX FIFO is empty.

UTXFF2: UART2 transmit FIFO full. The meaning of this bit depends on the state of the UFIFOEN bit in the UART2 bit rate and line control register. If the FIFO is disabled, this bit will be set when the TX holding register is full. If the FIFO is enabled, the UTXFF bit will be set when the TX FIFO is full. Table 33. SYSFLG2

DS474PP1

EP7212 5.3

Interrupt Registers

5.3.1

INTSR1 Interrupt Status Register 1

ADDRESS: 0x8000.0240 15

SSEOTI

UMSINT

URXINT1

UTXINT1

TINT

RTCMI

TC2OI

TC1OI

EINT3

EINT2

EINT1

CSINT

MCINT

WEINT

BLINT

EXTFIQ

The interrupt status register is a 32-bit read only register. The interrupt status register reflects the current state of the first 16 interrupt sources within the EP7212. Each bit is set if the appropriate interrupt is active. The interrupt assignment is given in Table 34. Bit

Description

EXTFIQ: External fast interrupt. This interrupt will be active if the nEXTFIQ input pin is forced low and is mapped to the FIQ input on the ARM720T processor.

BLINT: Battery low interrupt. This interrupt will be active if no external supply is present (nEXTPWR is high) and the battery OK input pin BATOK is forced low. This interrupt is de-glitched with a 16 kHz clock, so it will only generate an interrupt if it is active for longer than 125 µsec. It is mapped to the FIQ input on the ARM720T processor and is cleared by writing to the BLEOI location. NOTE: BLINT is disabled during the Standby State.

WEINT: Tick Watch dog expired interrupt. This interrupt will become active on a rising edge of the periodic 64 Hz tick interrupt clock if the tick interrupt is still active (i.e., if a tick interrupt has not been serviced for a complete tick period). It is mapped to the FIQ input on the ARM720T processor and the TEOI location. NOTE: WEINT is disabled during the Standby State. Watch dog timer tick rate is 64 Hz (in 13 MHz and 73.728–18.432 MHz modes). Watchdog timer is turned off during the Standby State.

MCINT: Media changed interrupt. This interrupt will be active after a rising edge on the nMEDCHG input pin has been detected, This input is de-glitched with a 16 kHz clock so it will only generate an interrupt if it is active for longer than 125 µsec. It is mapped to the FIQ input on the ARM7TDMI processor and is cleared by writing to the MCEOI location. On power-up, the Media change pin (nMEDCHG) is used as an input to force the processor to either boot from the internal Boot ROM, or from external memory. After power-up, the pin can be used as a general purpose FIQ interrupt pin.

CSINT: Codec sound interrupt, generated when the data FIFO has reached half full or empty (depending on the interface direction). It is cleared by writing to the COEOI location.

EINT1: External interrupt input 1. This interrupt will be active if the nEINT1 input is active (low). It is cleared by returning nEINT1 to the passive (high) state.

EINT2: External interrupt input 2. This interrupt will be active if the nEINT2 input is active (low). It is cleared by returning nEINT2 to the passive (high) state.

EINT3: External interrupt input 3. This interrupt will be active if the EINT3 input is active (high). It is cleared by returning EINT3 to the passive (low) state.

TC1OI: TC1 under flow interrupt. This interrupt becomes active on the next falling edge of the timer counter 1 clock after the timer counter has under flowed (reached zero). It is cleared by writing to the TC1EOI location. Table 34. INTSR1

DS474PP1

EP7212 Bit

Description

TC2OI: TC2 under flow interrupt. This interrupt becomes active on the next falling edge of the timer counter 2 clock after the timer counter has under flowed (reached zero). It is cleared by writing to the TC2EOI location.

RTCMI: RTC compare match interrupt. This interrupt becomes active on the next rising edge of the 1 Hz Real Time Clock (one second later) after the 32-bit time written to the Real Time Clock match register exactly matches the current time in the RTC. It is cleared by writing to the RTCEOI location.

TINT: 64 Hz tick interrupt. This interrupt becomes active on every rising edge of the internal 64 Hz clock signal. This 64 Hz clock is derived from the 15-stage ripple counter that divides the 32.768 kHz oscillator input down to 1 Hz for the Real Time Clock. This interrupt is cleared by writing to the TEOI location. NOTE: TINT is disabled / turned off during the Standby State.

UTXINT1: Internal UART1 transmit FIFO half-empty interrupt. The function of this interrupt source depends on whether the UART1 FIFO is enabled. If the FIFO is disabled (FIFOEN bit is clear in the UART1 bit rate and line control register), this interrupt will be active when there is no data in the UART1 TX data holding register and be cleared by writing to the UART1 data register. If the FIFO is enabled this interrupt will be active when the UART1 TX FIFO is half or more empty, and is cleared by filling the FIFO to at least half full.

URXINT1: Internal UART1 receive FIFO half full interrupt. The function of this interrupt source depends on whether the UART1 FIFO is enabled. If the FIFO is disabled this interrupt will be active when there is valid RX data in the UART1 RX data holding register and be cleared by reading this data. If the FIFO is enabled this interrupt will be active when the UART1 RX FIFO is half or more full or if the FIFO is non empty and no more characters have been received for a three character time out period. It is cleared by reading all the data from the RX FIFO.

UMSINT: Internal UART1 modem status changed interrupt. This interrupt will be active if either of the two modem status lines (CTS or DSR) change state. It is cleared by writing to the UMSEOI location.

SSEOTI: Synchronous serial interface end of transfer interrupt. This interrupt will be active after a complete data transfer to and from the external ADC has been completed. It is cleared by reading the ADC data from the SYNCIO register. Table 34. INTSR1 (cont.)

5.3.2

INTMR1 Interrupt Mask Register 1

ADDRESS: 0x8000.0280 15

SSEOTI

UMSINT

URXINT

UTXINT

TINT

RTCMI

TC2OI

TC1OI

EINT3

EINT2

EINT1

CSINT

MCINT

WEINT

BLINT

EXTFIQ

This interrupt mask register is a 32-bit read / write register, which is used to selectively enable any of the first 16 interrupt sources within the EP7212. The four shaded interrupts all generate a fast interrupt request to the ARM720T processor (FIQ), this will cause a jump to processor virtual address 0000.0001C. All other interrupts will generate a standard interrupt request (IRQ), this will cause a jump to processor virtual address 0000.00018. Setting the appropriate bit in this register enables the corresponding interrupt. All bits are cleared by a system reset. Please refer to INTSR1 Interrupt Status Register 1 for individual bit details.

DS474PP1

EP7212 5.3.3

INTSR2 Interrupt Status Register 2

ADDRESS: 0x8000.1240 15:14

11:3

Reserved

URXINT2

UTXINT2

Reserved

SS2TX

SS2RX

KBDINT

This register is an extension of INTSR1, containing status bits for backward compatibility with CLPS7111. The interrupt status register also reflects the current state of the new interrupt sources within the EP7212. Each bit is set if the appropriate interrupt is active. The interrupt assignment is given in Table 35. Bit

Description

KBDINT: Keyboard interrupt. This interrupt is generated whenever a key is pressed, from the logical OR of the first 6 or all 8 of the Port A inputs (depending on the state of the KBD6 bit in the SYSCON2 register. The interrupt request is latched and can be de-asserted by writing to the KBDEOI location. NOTE: KBDINT is not deglitched.

SS2RX: Synchronous serial interface 2 receives FIFO half or greater full interrupt. This is generated when RX FIFO contains 8 or more half-words. This interrupt is cleared only when the RX FIFO is emptied or one SSI2 clock after RX is disabled.

SS2TX: Synchronous serial interface 2 transmit FIFO less than half empty interrupt. This is generated when TX FIFO contains fewer than 8 byte pairs. This interrupt gets cleared by loading the FIFO with more data or disabling the TX. One synchronization clock required when disabling the TX side before it takes effect.

UTXINT2: UART2 transmit FIFO half empty interrupt. The function of this interrupt source depends on whether the UART2 FIFO is enabled. If the FIFO is disabled (FIFOEN bit is clear in the UART2 bit rate and line control register), this interrupt will be active when there is no data in the UART2 TX data holding register and be cleared by writing to the UART2 data register. If the FIFO is enabled, this interrupt will be active when the UART2 TX FIFO is half or more empty and is cleared by filling the FIFO to at least half full.

URXINT2: UART2 receive FIFO half full interrupt. The function of this interrupt source depends on whether the UART2 FIFO is enabled. If the FIFO is disabled, this interrupt will be active when there is valid RX data in the UART2 RX data holding register and be cleared by reading this data. If the FIFO is enabled, this interrupt will be active when the UART2 RX FIFO is half or more full or if the FIFO is non-empty, and no more characters have been received for a three-character timeout period, t is cleared by reading all the data from the RX FIFO. Table 35. INSTR2

5.3.4

INTMR2 Interrupt Mask Register 2

ADDRESS: 0x8000.1280 15:14

11:3

Reserved

URXINT2

UTXINT2

Reserved

SS2TX

SS2RX

KBDINT

This register is an extension of INTMR1, containing interrupt mask bits for the backward compatibility with the CL-PS7111. Please refer to INTSR2 for individual bit details.

DS474PP1

EP7212 5.3.5

INTSR3 Interrupt Status Register 3

ADDRESS: 0x8000.2240 7:1

Reserved

DAIINT

This register is an extension of INTSR1 and INTSR2 containing status bits for the new features of the EP7212. Each bit is set if the appropriate interrupt is active. The interrupt assignment is given in Table 36. Bit 0

Description DAIINT: DAI interface interrupt. The cause must be determined by reading the DAI status register. It is mapped to the FIQ interrupt on the ARM720T processor Table 36. INTSR3

5.3.6

INTMR3 Interrupt Mask Register 3

ADDRESS: 0x8000.2280 7:1

Reserved

DAIINT

This register is an extension of INTMR1 and INTMR2, containing interrupt mask bits for the new features of the EP7212. Please refer to INTSR3 for individual bit details.

DS474PP1

EP7212 5.4

Memory Configuration Registers

5.4.1

MEMCFG1 Memory Configuration Register 1

ADDRESS: 0x8000.0180 31:24 nCS[3] configuration

23:16 nCS[2] configuration

15:8 nCS[1] configuration

7:0 nCS[0] configuration

Expansion and ROM space is selected by one of eight chip selects. One of the chip selects (nCS[6]) is used internally for the on-chip SRAM, and the configuration is hardwired for 32-bit-wide, minimumwait-state operation. nCS[7] is used for the on-chip Boot ROM and the configuration field is hardwired for 8-bit-wide, minimum-wait-state operation. Data written to the configuration fields for either nCS[6] or nCS7 will be ignored. Two of the chip selects (nCS[4:5]) can be used to access two CL-PS6700 PC CARD controller devices, and when either of these interfaces is enabled, the configuration field for the appropriate chip select in the MEMCFG2 register is ignored. When the PC CARD1 or 2 control bit in the SYSCON2 register is disabled, then nCS[4] and nCS[5] are active as normal and can be programmed using the relevant fields of MEMCFG2, as for the other four chip selects. All of the six external chip selects are active for 256 Mbytes and the timing and bus transfer width can be programmed individually. This is accomplished by programming the six-byte-wide fields contained in two 32-bit registers, MEMCFG1 and MEMCFG2. All bits in these registers are cleared by a system reset (except for the nCS[6] and nCS[7] configurations). The Memory Configuration Register 1 is a 32-bit read / write register which sets the configuration of the four expansion and ROM selects nCS[0:3]. Each select is configured with a 1-byte field starting with expansion select 0.

5.4.2

MEMCFG2 Memory Configuration Register 2

ADDRESS: 0x8000.01C0 31:24 (Boot ROM) 7 CLKENB

23:16 (Local SRAM) 6 SQAEN

15:8 nCS[5] configuration 5:2 Wait States Field

7:0 nCS[4] configuration 1:0 Bus width

The Memory Configuration Register 2 is a 32-bit read / write register which sets the configuration of the two expansion and ROM selects nCS[4:5]. Each select is configured with a 1-byte field starting with expansion select 4. Each of the six non-reserved byte fields for chip select configuration in the memory configuration registers are identical and define the number of wait states, the bus width, enable EXPCLK output during accesses and enable sequential mode access. This byte field is defined below. This arrangement applies to nCS[0:3], and nCS[4:5] when the PC CARD enable bits in the SYSCON2 register are not set. The state of these bits is ignored for the Boot ROM and local SRAM fields in the MEMCFG2 register. Table 37 defines the bus width field. Note that the effect of this field is dependent on the two BOOTBIT bits that can be read in the SYSFLG1 register. All bits in the memory configuration register are cleared by a system reset, and the state of the BOOTBIT bits are determined by Port E bits 0 and 1 on the EP7212 during power-on reset. The state of PE[1] and PE[0] determine whether the EP7212 is going to boot from either 32-bit-wide, 16-bit-wide or 8-bit-wide ROMs. Table 38 shows the values for the wait states for random and sequential wait states at 13 and 18 MHz bus rates. At 36 MHz bus rate, the encoding becomes more complex. Table 39 preserves compatibility with the previous devices, while allowing the previously unused bit combinations to specify more variations of random and sequential wait states.

DS474PP1

EP7212 Bus Width Field

BOOTBIT1

BOOTBIT0

Expansion Transfer Mode

Port E bits 1,0 during NPOR reset

32-bit wide bus access

Low, Low

16-bit wide bus access

Low, Low

8-bit wide bus access

Low, Low

Reserved

Low, Low

8-bit wide bus access

Low, High

Reserved

Low, High

32-bit wide bus access

Low, High

16-bit wide bus access

Low, High

16-bit wide bus access

High, Low

32-bit wide bus access

High, Low

Reserved

High, Low

8-bit wide bus access

High, Low

Table 37. Values of the Bus Width Field Value

No. of Wait States Random

No. of Wait States Sequential

Table 38. Values of the Wait State Field at 13 MHz and 18 MHz Bit 3

Bit 2

Bit 1

Bit 0

0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1

0 0 0 0 1 1 1 1 0 0 0 0 1 1 1 1

0 0 1 1 0 0 1 1 0 0 1 1 0 0 1 1

0 1 0 1 0 1 0 1 0 1 0 1 0 1 0 1

Wait States Random 8 7 6 5 4 3 2 1 8 7 6 5 4 3 2 1

Wait States Sequential 3 3 3 3 2 2 2 2 1 1 1 1 0 0 0 0

Table 39. Values of the Wait State Field at 36 MHz

DS474PP1

EP7212 Bit

Description

SQAEN: Sequential access enable. Setting this bit will enable sequential accesses that are on a quad word boundary to take advantage of faster access times from devices that support page mode. The sequential access will be faulted after four words (to allow video refresh cycles to occur), even if the access is part of a longer sequential access. In addition, when this bit is not set, non-sequential accesses will have a single idle cycle inserted at least every four cycles so that the chip select is de-asserted periodically between accesses for easier debug.

CLKENB: Expansion clock enable. Setting this bit enables the EXPCLK to be active during accesses to the selected expansion device. This will provide a timing reference for devices that need to extend bus cycles using the EXPRDY input. Back-to-back (but not necessarily page mode) accesses will result in a continuous clock. This bit will only affect EXPCLK when the PLL is being used (i.e., in 73.728â&#x20AC;&#x201C;18.432 MHz mode). When operating in 13 MHz mode, the EXPCLK pin is an input, so it is not affected by this register bit. To save power internally, it should always be set to zero when operating in 13 MHz mode. Table 40. MEMCFG See the AC Electrical Specification section for more detail on bus timing. The memory area decoded by CS[6] is reserved for the on-chip SRAM, hence this does not require a configuration field in MEMCFG2. It is automatically set up for 32-bit-wide, no-wait-state accesses. For the Boot ROM, it is automatically set up for 8-bit, no wait state accesses. Chip selects nCS[4] and nCS[5] are used to select two CL-PS6700 PC CARD controller devices. These have a multiplexed 16-bit wide address / data interface, and the configuration bytes in the MEMCFG2 register have no meaning when these interfaces are enabled.

DS474PP1

EP7212 5.5 5.5.1

Timer / Counter Registers TC1D Timer Counter 1 Data Register

ADDRESS: 0x8000.0300 The timer counter 1 data register is a 16-bit read / write register which sets and reads data to TC1. Any value written will be decremented on the next rising edge of the clock.

5.5.2

TC2D Timer Counter 2 Data Register

ADDRESS: 0x8000.0340 The timer counter 2 data register is a 16-bit read / write register which sets and reads data to TC2. Any value written will be decremented on the next rising edge of the clock.

5.5.3

RTCDR Real Time Clock Data Register

ADDRESS: 0x8000.0380 The Real Time Clock data register is a 32-bit read / write register, which sets and reads the binary time in the RTC. Any value written will be incremented on the next rising edge of the 1 Hz clock. This register is reset only by nPOR.

5.5.4

RTCMR Real Time Clock Match Register

ADDRESS: 0x8000.03C0 The Real Time Clock match register is a 32-bit read / write register, which sets and reads the binary match time to RTC. Any value written will be compared to the current binary time in the RTC, if they match it will assert the RTCMI interrupt source. This register is reset only by nPOR.

DS474PP1

EP7212 5.6

LEDFLSH Register

ADDRESS: 0x8000.22C0 6

5:2

1:0

Enable

Duty ratio

Flash rate

The output is enabled whenever LEDFLSH[6] = 1. When enabled, PDDDR[0] needs to be configured as an output pin and the bit cleared to ‘0’ (See PDDDR Port D Data Direction Register). When the LED Flasher is disabled, the pin defaults to being used as Port D bit 0. Thus, this will ensure that the LED will be off when disabled. The flash rate is determined by the LEDFLSH[1:0] bits, in the following way:

LEDFLSH[1:0]

Flash Period (sec)

4 Table 41. LED Flash Rates

LEDFLSH[5:2]

Duty Ratio (time on: time off)

LEDFLSH[5:2]

Duty Ratio (time on: time off)

0000